JD Ceramics has been specializing in the field of air interlacing jets,air texturizing jets,and water jets over 29 years.With several years of technical accumulation and continuous equipments upgrades,we have been con...JD Ceramics has been specializing in the field of air interlacing jets,air texturizing jets,and water jets over 29 years.With several years of technical accumulation and continuous equipments upgrades,we have been consistently delivering high-precision,highquality,cost-effective ceramic nozzle solutions to the market.展开更多
Rolled Mg-Al-Sn series alloys generally possess limited formability due to the formation of strong basal texture.Texture weakening is an effective way to enhance formability,but usually accompanied with decreasing str...Rolled Mg-Al-Sn series alloys generally possess limited formability due to the formation of strong basal texture.Texture weakening is an effective way to enhance formability,but usually accompanied with decreasing strength.In this work,synergistic enhancement of strength and formability is achieved in a Mg-3Al-1Sn-0.5Ca-0.1Sm(ATXS3110)alloy by 0.2 wt.%Mn addition combined with high temperature rolling,exhibiting a high index Erichsen(I.E.)value of~8.1 mm and near-isotropic mechanical properties.On one hand,after Mn addition,the grain refinement from~7.6μm to~4.1μm results in suppression of extension twinning,thereby preventing the development of strong basal texture upon stretch forming.On the other hand,trace Mn addition narrows the grain size distribution and promotes the formation of uniform fine grains,which induces homogeneous deformation during stretch forming.Moreover,grain refinement and high-density nano-sized precipitates caused by trace Mn addition increase the strength.This work may provide insights into designing low-cost Mg-Al-Sn series alloys with superior comprehensive mechanical properties for further structural applications.展开更多
The textures and microstructures of hot-and cold-rolled sheets of an AA 5454 aluminium alloy were studied,with special attention paid to comparing the texture development for the symmetric and asymmetric cold rolling....The textures and microstructures of hot-and cold-rolled sheets of an AA 5454 aluminium alloy were studied,with special attention paid to comparing the texture development for the symmetric and asymmetric cold rolling.Scanning electron microscopy with electron-backscatter diffraction was used to monitor the development of the microstructure in the differently deformed and additionally annealed samples.Details of the formations and transformations of individual texture components occurring during the rolling processes were observed and discussed.The average grain sizes,textures and mechanical properties were correlated and explained for the symmetric and asymmetric cold-rolled samples.The asymmetric rolling is beneficial in terms of deep drawability because it reduces the planar anisotropy of the annealed material due to the decrease of the Cube,Goss,rotated-Cube and η-fibre texture components and at the same time strengthens X1-and X2-fibre texture components which are shear texture components and improve deep drawability.During the asymmetric cold rolling,the temperature increases due to friction,triggering recrystallisation processes and leading to larger grains.It is also confirmed that asymmetric cold rolling uses less rolling force and consequently less energy to produce a final material with better formability,particularly earing.展开更多
An internal state variable(ISV)model was established according to the experimental results of hot plane strain compression(PSC)to predict the microstructure evolution during hot spinning of ZK61 alloy.The effects of t...An internal state variable(ISV)model was established according to the experimental results of hot plane strain compression(PSC)to predict the microstructure evolution during hot spinning of ZK61 alloy.The effects of the internal variables were considered in this ISV model,and the parameters were optimized by genetic algorithm.After validation,the ISV model was used to simulate the evolution of grain size(GS)and dynamic recrystallization(DRX)fraction during hot spinning via Abaqus and its subroutine Vumat.By comparing the simulated results with the experimental results,the application of the ISV model was proven to be reliable.Meanwhile,the strength of the thin-walled spun ZK61 tube increased from 303 to 334 MPa due to grain refinement by DRX and texture strengthening.Besides,some ultrafine grains(0.5μm)that played an important role in mechanical properties were formed due to the proliferation,movement,and entanglement of dislocations during the spinning process.展开更多
Rare-earth(RE) magnesium alloys have attracted lots of attention due to their excellent mechanical properties.In this work,the microstructure and mechanical properties of as-extruded 8.5Gd-4.5Y-0.8Zn-0.4Zr magnesium a...Rare-earth(RE) magnesium alloys have attracted lots of attention due to their excellent mechanical properties.In this work,the microstructure and mechanical properties of as-extruded 8.5Gd-4.5Y-0.8Zn-0.4Zr magnesium alloy under different solution treatment were examined with the optical microscope(OM),scanning electron microscope(SEM),high resolution transmission electron microscope(HRTEM),electron back-scattered diffraction(EBSD) and Instron testing machine.The results show that the ES12alloy(solution treatment for 12 h at 520℃) has the highest ultimate tensile strength(UTS) of 390 MPa with a fracture elongation of 24.5% at the co st of a minor drop in yielding strength(YS) compared to the asextruded alloy.During solution treatment,the block-shaped long period stacking ordered(LPSO) in asextruded alloy evolves into plate-shaped LPSO,which disperses at grain boundaries(GBs),and lamellar LPSO,which distributes in grains.The coexistence of plate-shaped and lamellar LPSO,which impedes the dislocations movement,and the activated dislocations are regarded as the primary reasons for mechanical properties improvement.Furthermore,the(11-21) <1-100> texture in as-extruded alloy transforms into the(11-20) <0001> texture in ES12 alloy.The average grain size increases from 3.45 μm in as-extruded alloy to 18.70 μm in ES12 alloy.The Schmid factors of {0001} <11-20>,{10-10} <11-20>,{10-11} <11-20>,and {11-22} <11-23> increase,which indicate that slip systems are more easily activated in plastic deformation.The dynamic recrystallization(DRX) grains fraction increase to 92.8% for ES12 alloy due to the particle-stimulated nucleation(PSN) mechanism triggered by block-shaped and plate-shaped LPSO.The freshly DRXed grains further weaken the texture,and reduce the dislocation density.All of these factors increase elongation of RE magnesium alloy.展开更多
Hot deformation with high strain rate has been paid more attention due to its high efficiency and low cost,however,the strain rate dependent dynamic recrystallization(DRX)and texture evolution in hot deformation proce...Hot deformation with high strain rate has been paid more attention due to its high efficiency and low cost,however,the strain rate dependent dynamic recrystallization(DRX)and texture evolution in hot deformation process,which affect the formability of metals,are lack of study.In this work,the DRX behavior and texture evolution of Mg-8Gd-1Er-0.5Zr alloy hot compressed with strain rates of 0.1 s^(−1),1 s^(−1),10 s^(−1) and 50 s^(−1) are studied,and the corresponding dominant mechanisms for DRX and texture weakening are discussed.Results indicated the DRX fraction was 20%and the whole texture intensity was 16.89 MRD when the strain rate was 0.1 s^(−1),but they were 76%and 6.55 MRD,respectively,when the strain rate increased to 50 s^(−1).The increment of DRX fraction is suggested to result from the reduced DRX critical strain and the increased dislocation density as well as velocity,while the weakened whole texture is attributed to the increased DRX grains.At the low strain rate of 0.1 s^(−1),discontinuous DRX(DDRX)was the dominant,but the whole texture was controlled by the deformed grains with the preferred orientation of{0001}⊥CD,because the number of DDRX grains was limited.At the high strain rate of 50 s^(−1),continuous DRX(CDRX)and twin-induced DRX(TDRX)were promoted,and more DRX grains resulted in orientation randomization.The whole texture was mainly weakened by CDRX and TDRX grains,in which CDRX plays a major role.The results of present work are significant for understanding the hot workability of Mg-RE alloys with a high strain rate.展开更多
Conventional rolled Mg-Al alloy sheets typically exhibit strong basal textures that remain and may even strengthen after recrystallization annealing due to the preferential growth of basal-oriented grains,resulting in...Conventional rolled Mg-Al alloy sheets typically exhibit strong basal textures that remain and may even strengthen after recrystallization annealing due to the preferential growth of basal-oriented grains,resulting in poor formability at room temperature.Therefore,the knowledge of recrystallization and grain growth is critical for modifying textures of Mg-Al alloy sheets.The static recrystallization and texture evolution in a cold-rolled dilute Mg-1Al(wt.%)alloy during various annealed temperatures ranging from 300℃ to 450℃,have been investigated using the quasi in-situ electron backscatter diffraction(EBSD)method.The as-rolled Mg-1Al alloy shows a dominant basal texture,which weakens and broadens in the rolling direction(RD)during the subsequent annealing,accompanied by the formation of{1010}texture component.Particularly,the {1010} texture component is more pronounced after annealing at high temperatures.The quasi in-situ EBSD results show that recrystallized grains are mainly induced by shear bands,which exhibit a wide spectrum of orientations with c-axis tilt angles ranging 20°-45°from the normal direction(ND).Orientations of shear band-induced recrystallized grains are retained during the entire recrystallization process,resulting in a reduction in the texture intensity.Moreover,recrystallized grains belonging to the {1010}texture component grow preferentially compared to those with other orientations,which is attributed to low energy grain boundaries,especially grain boundaries with∼30°misorientation angles.Furthermore,the high temperature annealing facilitates the rapid growth of grain boundaries having a 30°misorientation angle,leading to the occurrence of distinct {1010} texture after annealing at 450℃ for 1 h.The results provide insights for texture modification of rare earth-free low-alloyed Mg alloys by controlling annealing parameters.展开更多
Monitoring minuscule mechanical signals,both in magnitude and direction,is imperative in many application scenarios,e.g.,structural health monitoring and robotic sensing systems.However,the piezoelectric sensor strugg...Monitoring minuscule mechanical signals,both in magnitude and direction,is imperative in many application scenarios,e.g.,structural health monitoring and robotic sensing systems.However,the piezoelectric sensor struggles to satisfy the requirements for directional recognition due to the limited piezoelectric coefficient matrix,and achieving sensitivity for detecting micrometer-scale deformations is also challenging.Herein,we develop a vector sensor composed of lead zirconate titanate-electronic grade glass fiber composite filaments with oriented arrangement,capable of detecting minute anisotropic deformations.The as-prepared vector sensor can identify the deformation directions even when subjected to an unprecedented nominal strain of 0.06%,thereby enabling its utility in accurately discerning the 5μm-height wrinkles in thin films and in monitoring human pulse waves.The ultra-high sensitivity is attributed to the formation of porous ferroelectret and the efficient load transfer efficiency of continuous lead zirconate titanate phase.Additionally,when integrated with machine learning techniques,the sensor’s capability to recognize multi-signals enables it to differentiate between 10 types of fine textures with 100%accuracy.The structural design in piezoelectric devices enables a more comprehensive perception of mechanical stimuli,offering a novel perspective for enhancing recognition accuracy.展开更多
Machine learning(ML)is increasingly applied for medical image processing with appropriate learning paradigms.These applications include analyzing images of various organs,such as the brain,lung,eye,etc.,to identify sp...Machine learning(ML)is increasingly applied for medical image processing with appropriate learning paradigms.These applications include analyzing images of various organs,such as the brain,lung,eye,etc.,to identify specific flaws/diseases for diagnosis.The primary concern of ML applications is the precise selection of flexible image features for pattern detection and region classification.Most of the extracted image features are irrelevant and lead to an increase in computation time.Therefore,this article uses an analytical learning paradigm to design a Congruent Feature Selection Method to select the most relevant image features.This process trains the learning paradigm using similarity and correlation-based features over different textural intensities and pixel distributions.The similarity between the pixels over the various distribution patterns with high indexes is recommended for disease diagnosis.Later,the correlation based on intensity and distribution is analyzed to improve the feature selection congruency.Therefore,the more congruent pixels are sorted in the descending order of the selection,which identifies better regions than the distribution.Now,the learning paradigm is trained using intensity and region-based similarity to maximize the chances of selection.Therefore,the probability of feature selection,regardless of the textures and medical image patterns,is improved.This process enhances the performance of ML applications for different medical image processing.The proposed method improves the accuracy,precision,and training rate by 13.19%,10.69%,and 11.06%,respectively,compared to other models for the selected dataset.The mean error and selection time is also reduced by 12.56%and 13.56%,respectively,compared to the same models and dataset.展开更多
Ecological monitoring vehicles are equipped with a range of sensors and monitoring devices designed to gather data on ecological and environmental factors.These vehicles are crucial in various fields,including environ...Ecological monitoring vehicles are equipped with a range of sensors and monitoring devices designed to gather data on ecological and environmental factors.These vehicles are crucial in various fields,including environmental science research,ecological and environmental monitoring projects,disaster response,and emergency management.A key method employed in these vehicles for achieving high-precision positioning is LiDAR(lightlaser detection and ranging)-Visual Simultaneous Localization and Mapping(SLAM).However,maintaining highprecision localization in complex scenarios,such as degraded environments or when dynamic objects are present,remains a significant challenge.To address this issue,we integrate both semantic and texture information from LiDAR and cameras to enhance the robustness and efficiency of data registration.Specifically,semantic information simplifies the modeling of scene elements,reducing the reliance on dense point clouds,which can be less efficient.Meanwhile,visual texture information complements LiDAR-Visual localization by providing additional contextual details.By incorporating semantic and texture details frompaired images and point clouds,we significantly improve the quality of data association,thereby increasing the success rate of localization.This approach not only enhances the operational capabilities of ecological monitoring vehicles in complex environments but also contributes to improving the overall efficiency and effectiveness of ecological monitoring and environmental protection efforts.展开更多
BACKGROUND Microvascular invasion(MVI)is a significant risk factor for recurrence and metastasis following hepatocellular carcinoma(HCC)surgery.Currently,there is a paucity of preoperative evaluation approaches for MV...BACKGROUND Microvascular invasion(MVI)is a significant risk factor for recurrence and metastasis following hepatocellular carcinoma(HCC)surgery.Currently,there is a paucity of preoperative evaluation approaches for MVI.AIM To investigate the predictive value of texture features and radiological signs based on multiparametric magnetic resonance imaging in the non-invasive preoperative prediction of MVI in HCC.METHODS Clinical data from 97 HCC patients were retrospectively collected from January 2019 to July 2022 at our hospital.Patients were classified into two groups:MVI-positive(n=57)and MVI-negative(n=40),based on postoperative pathological results.The correlation between relevant radiological signs and MVI status was analyzed.MaZda4.6 software and the mutual information method were employed to identify the top 10 dominant texture features,which were combined with radiological signs to construct artificial neural network(ANN)models for MVI prediction.The predictive performance of the ANN models was evaluated using area under the curve,sensitivity,and specificity.ANN models with relatively high predictive performance were screened using the DeLong test,and the regression model of multilayer feedforward ANN with backpropagation and error backpropagation learning method was used to evaluate the models’stability.RESULTS The absence of a pseudocapsule,an incomplete pseudocapsule,and the presence of tumor blood vessels were identified as independent predictors of HCC MVI.The ANN model constructed using the dominant features of the combined group(pseudocapsule status+tumor blood vessels+arterial phase+venous phase)demonstrated the best predictive performance for MVI status and was found to be automated,highly operable,and very stable.CONCLUSION The ANN model constructed using the dominant features of the combined group can be recommended as a noninvasive method for preoperative prediction of HCC MVI status.展开更多
Impact of texture type on the magnetic properties of ultrahigh density perpendicular magnetic recording media L1_(0)-FePt thin film was investigated,so were the texture formation and evolution mechanism.Reuss,Voigt,an...Impact of texture type on the magnetic properties of ultrahigh density perpendicular magnetic recording media L1_(0)-FePt thin film was investigated,so were the texture formation and evolution mechanism.Reuss,Voigt,and Hill models were used to determine the anisotropic elastic modulus of L1_(0)-FePt thin film with fiber texture.Then,the elastic strain energies of thin films under various stress conditions were calculated.Results reveal that the stress condition has a significant influence on the fiber texture evolution.When the L1_(0)-FePt thin film is subjected to compressive in-plane strain prior to ordering phase transformation,the formation of{100}fiber texture is promoted.On the contrary,the ordering phase transformation under tensile in-plane strain promotes the{001}fiber texture formation.展开更多
Efficient tool condition monitoring techniques help to realize intelligent management of tool life and reduce tool usage costs.In this paper,the influence of different wear degrees of ball-end milling cutters on the t...Efficient tool condition monitoring techniques help to realize intelligent management of tool life and reduce tool usage costs.In this paper,the influence of different wear degrees of ball-end milling cutters on the texture shape of machining tool marks is investigated,and a method is proposed for predicting the wear state(including the position and degree of tool wear)of ball-end milling cutters based on entropy measurement of tool mark texture images.Firstly,data samples are prepared through wear experiments,and the change law of the tool mark texture shape with the tool wear state is analyzed.Then,a two-dimensional sample entropy algorithm is developed to quantify the texture morphology.Finally,the processing parameters and tool attitude are integrated into the prediction process to predict the wear value and wear position of the ball end milling cutter.After testing,the correlation between the predicted value and the standard value of the proposed tool condition monitoring method reaches 95.32%,and the accuracy reaches 82.73%,indicating that the proposed method meets the requirement of tool condition monitoring.展开更多
The difference in the microstructure,texture in the stir zone(SZ)of the AZ31(Mg-3 Al-1 Zn,wt.%)alloy after friction stir welding(FSW)and subsequent annealing at 400℃for 1 h was characterized by scanning electron micr...The difference in the microstructure,texture in the stir zone(SZ)of the AZ31(Mg-3 Al-1 Zn,wt.%)alloy after friction stir welding(FSW)and subsequent annealing at 400℃for 1 h was characterized by scanning electron microscopy(SEM)with electron backscatter diffraction(EBSD)measurements at the surface and core regions.The findings indicate that FSW produced grain refinement where the mean grain size decreases from 19μm(base metal)to 5.1 and 3.5μm at the surface and core regions,respectively.The c-axis of the grains at the surface region was aligned with the normal direction(<0001>//ND)due to the additional strain of the tool shoulder.In contrast,the core region shows a typical shear texture,where the c-axis tends to be oriented parallel to the welding direction(<0001>//WD).The Vickers microhardness mapping across the SZ revealed that the core region was soften than the surface region due to the dynamic recrystallization and texture weakening.The microstructure of the SZ remains principally deformed after annealing treatment except for the development of massive Mg_(17)Al_(12)precipitates and the abnormal grain growth of a few grains with<11-20>//WD orientation at the upper side of the surface region.The c-axis of the grains at the surface region was tilted about 10°toward WD,while an inclined<0001>//WD orientation about 30°from WD was developed at the core region.Consequently,the distribution of microhardness values across the SZ was more heterogeneous than the FSW sample.The results were discussed in the light of grain boundary misorientation,dislocation density and the pinning effect of Mg_(17)Al_(12)precipitates.Additionally,Schmid factor analysis was used to examine the activation of the basal slip mode to characterize the associated mechanical response.展开更多
Accurate and robust navigation in complex surgical environments is crucial for bronchoscopic surgeries.This study purposes a bronchoscopic lumen feature matching network(BLFM-Net)based on deep learning to address the ...Accurate and robust navigation in complex surgical environments is crucial for bronchoscopic surgeries.This study purposes a bronchoscopic lumen feature matching network(BLFM-Net)based on deep learning to address the challenges of image noise,anatomical complexity,and the stringent real-time requirements.The BLFM-Net enhances bronchoscopic image processing by integrating several functional modules.The FFA-Net preprocessing module mitigates image fogging and improves visual clarity for subsequent processing.The feature extraction module derives multi-dimensional features,such as centroids,area,and shape descriptors,from dehazed images.The Faster RCNN Object detection module detects bronchial regions of interest and generates bounding boxes to localize key areas.The feature matching module accelerates the process by combining detection boxes,extracted features,and a KD-Tree(K-Dimensional Tree)-based algorithm,ensuring efficient and accurate regional feature associations.The BLFM-Net was evaluated on 5212 bronchoscopic images,demonstrating superior performance compared to traditional and other deep learning-based image matching methods.It achieved real-time matching with an average frame time of 6 ms,with a matching accuracy of over 96%.The method remained robust under challenging conditions including frame dropping(0,5,10,20),shadowed regions,and variable lighting,maintaining accuracy of above 94%even with the frame dropping of 20.This study presents BLFM-Net,a deep learning-based matching network designed to enhance and match bronchial features in bronchoscopic images.The BLFM-Net shows improved accuracy,real-time performance,and reliability,making a valuable tool for bronchoscopic surgeries.展开更多
In this work,a good balance of strength and ductility(a yield strength of 185 MPa and a uniform elongation of 20%)has been obtained in a dilute Mg-1.8Zn-0.3Y-0.3Ca-0.3Zr(wt.%)alloy using hard plate rolling(HPR)followe...In this work,a good balance of strength and ductility(a yield strength of 185 MPa and a uniform elongation of 20%)has been obtained in a dilute Mg-1.8Zn-0.3Y-0.3Ca-0.3Zr(wt.%)alloy using hard plate rolling(HPR)followed by annealing,with a low anisotropy in mechanical properties.More importantly,the HPR-annealed alloy shows an excellent formability at the same time,i.e.,the index Erichsen(I.E.)value reaches 7.9 mm(the Erichsen cupping test)at room temperature,which is higher compared with the Mg-1.8Zn-0.3Y-0.3Ca0.3Zr alloy produced by conventional multi-pass rolling(CR)followed by annealing.The excellent synergy of strength and formability of the HPR-annealed alloy is mainly attributed to a weak elliptical ring texture,as well as finer and denser Zn_(2)Zr_(3)precipitates.The formation of weak elliptical ring texture is related to the preferential co-segregation of Zn and Ca elements at boundaries of basal grains with smal misorientation angles during annealing,which inhibits the growth of basal grains and promotes the preferential growth of non-basal grains At the same time,in comparison with the CR-annealed alloy,the HPR-annealed alloy contains finer and denser Zn_(2)Zr_(3)precipitates that ar less likely to become sources of cracks,leading to the higher strength and formability of the HPR-annealed alloy.The results in this work can provide reference for the development of high strength Mg alloy sheets with excellent room temperature formability,which also shed light on mitigating planar anisotropy in mechanical properties for Mg alloy sheets.展开更多
Panoramic images, offering a 360-degree view, are essential in virtual reality(VR) and augmented reality(AR), enhancing realism with high-quality textures. However, acquiring complete and high-quality panoramic textur...Panoramic images, offering a 360-degree view, are essential in virtual reality(VR) and augmented reality(AR), enhancing realism with high-quality textures. However, acquiring complete and high-quality panoramic textures is challenging. This paper introduces a method using generative adversarial networks(GANs) and the contrastive language-image pretraining(CLIP) model to restore and control texture in panoramic images. The GAN model captures complex structures and maintains consistency, while CLIP enables fine-grained texture control via semantic text-image associations. GAN inversion optimizes latent codes for precise texture details. The resulting low dynamic range(LDR) images are converted to high dynamic range(HDR) using the Blender engine for seamless texture blending. Experimental results demonstrate the effectiveness and flexibility of this method in panoramic texture restoration and generation.展开更多
A high-purity Ti sheet with dense preexisting twins(introduced by 10%cold rolling)was subjected to isochronal annealing at 500–800°C for 1 h and isothermal annealing at 600°C for 0.17–100 h,respectively.By...A high-purity Ti sheet with dense preexisting twins(introduced by 10%cold rolling)was subjected to isochronal annealing at 500–800°C for 1 h and isothermal annealing at 600°C for 0.17–100 h,respectively.By mainly utilizing electron backscatter diffraction(EBSD)and electron channel contrast(ECC)imaging techniques,the microstructure and texture evolution during the isochronal and isothermal annealing were investigated systematically.Results show that recrystallization nuclei appear in the specimen annealed at 600°C for 1 h.In contrast,recrystallization cannot be initiated for those annealed at lower temperatures or for a shorter time.With the increase in temperature or time,the fraction of the recrystallized structure increases with gradual grain coarsening.Nearly complete recrystallization is reached after 800°C-1 h or 600°C-100 h annealing.Due to the distribution heterogeneity of microstructure and stored energy induced by the dense preexisting twins,recrystallization nucleation preferentially occurs in some specific regions(twin-twin or twin-grain boundary junctions).Then,they selectively consume twin lamellar structures,leading to non-uniform grain growth.It is demonstrated that the recrystallization nucleation is dominated by the strain-induced boundary migration mechanism,allowing scattered texture components corresponding to the twin lamellar structures to be gradually encroached by those untwinned structures with the initial bimodal basal texture(BBT).Eventually,a strong BBT is always obtained after sufficient recrystallization.展开更多
Given the limitations of traditional hot extrusion methods in improving the microstructure and mechanical properties of magnesium(Mg)alloys,this paper attempts to treat AZ31 Mg alloy billet by pre-upsetting continuous...Given the limitations of traditional hot extrusion methods in improving the microstructure and mechanical properties of magnesium(Mg)alloys,this paper attempts to treat AZ31 Mg alloy billet by pre-upsetting continuous variable cross-section direct extrusion(U-CVCDE).The effects of dynamic recrystallization behavior and slip system activity on texture evolution and mechanical properties of CVCDE Mg alloys with different pre-upsetting amounts were systematically analyzed.The results indicate that the introduction of the pre-upsetting process promotes dynamic recrystallization during the CVCDE process.The recrystallization proportion shows a trend of first rising and then decreasing with the increase of the pre-upsetting amount.Among them,the proportion of recrystallization grains in the U2-CVCDE-formed structural parts is as high as 88.3%.The average grain sizes of U1-CVCDE,U2-CVCDE,and U3-CVCDE were 6.01μm,4.90μm,and10.45μm,respectively.In addition,following U-CVCDE,the pyramidal slip of each forming component consistently maintains a high level of activation and opening and dominates,making more grains deflect in the axial extrusion direction of C to varying degrees,which is conducive to the uniform distribution of stress in more grains during plastic deformation.The synergistic effect of dynamic recrystallization behavior and the high activity of the pyramidal slip system significantly weakened the(0001)basal texture strength,and the maximum basal texture strength showed a gradually decreasing trend,among which the base surface texture strength of U3-CVCDE formed parts was only 9.9.The U-CVCDE process is employed to achieve deep modification of Mg alloy,and excellent comprehensive mechanical properties are obtained;among them,the yield and tensile strength of U2-CVCDE are as high as 243.4 MPa and 317.5 MPa,respectively,and the elongation after breaking is up to 21.3%.This study introduces a practical new idea for investigating the extrusion forming technology of high-performance Mg alloys.展开更多
Cold-rolling was conducted on AZ31 magnesium alloy with fine and coarse grains to produce plates with high density of shear bands and{101^(-)1}twins,respectively.Then,these two kinds of plates are subjected to isother...Cold-rolling was conducted on AZ31 magnesium alloy with fine and coarse grains to produce plates with high density of shear bands and{101^(-)1}twins,respectively.Then,these two kinds of plates are subjected to isothermal annealing to reveal the effect of shear bands and{101^(-)1}twins on recrystallization behavior.During annealing,static recrystallization occurs firstly in shear band zones and{101^(-)1}twin zones,which has different effect on texture and mechanical properties.With the increase of annealing temperature,strong basal texture remains in annealed SG-17%while the basal texture is weakened gradually in annealed LG-15%.Recrystallized grains from twin zones have a random orientation which is responsible for the weakened basal texture in annealed LG-15%.In addition,microhardness decreases gradually with the prolonged annealing time due to static recrystallization.LG-15%has a lower recrystallization activation energy because{101^(-)1}twins are in favor of the nucleation and growth of recrystallized grains.After 500℃annealing,the yield strength decreases significantly with a significant improvement in failure strain.The annealed LG-15%has a much higher compressive strain than the annealed SG-17%due to texture weakening effect.展开更多
文摘JD Ceramics has been specializing in the field of air interlacing jets,air texturizing jets,and water jets over 29 years.With several years of technical accumulation and continuous equipments upgrades,we have been consistently delivering high-precision,highquality,cost-effective ceramic nozzle solutions to the market.
基金supported by The National Natural Science Foundation of China(under Nos.52234009,U19A2084,52171116,U22A20109,52201113)Partial financial support came from Program for the Central University Youth Innovation Team(419021423505)+2 种基金the Fundamental Research Funds for the Central Universities(No.2412022QD037)the Excellent Youth Program of Jilin Provincial Department of Education(JJKH20241425KJ)the Fundamental Research Funds for the Central Universities,JLU.
文摘Rolled Mg-Al-Sn series alloys generally possess limited formability due to the formation of strong basal texture.Texture weakening is an effective way to enhance formability,but usually accompanied with decreasing strength.In this work,synergistic enhancement of strength and formability is achieved in a Mg-3Al-1Sn-0.5Ca-0.1Sm(ATXS3110)alloy by 0.2 wt.%Mn addition combined with high temperature rolling,exhibiting a high index Erichsen(I.E.)value of~8.1 mm and near-isotropic mechanical properties.On one hand,after Mn addition,the grain refinement from~7.6μm to~4.1μm results in suppression of extension twinning,thereby preventing the development of strong basal texture upon stretch forming.On the other hand,trace Mn addition narrows the grain size distribution and promotes the formation of uniform fine grains,which induces homogeneous deformation during stretch forming.Moreover,grain refinement and high-density nano-sized precipitates caused by trace Mn addition increase the strength.This work may provide insights into designing low-cost Mg-Al-Sn series alloys with superior comprehensive mechanical properties for further structural applications.
文摘The textures and microstructures of hot-and cold-rolled sheets of an AA 5454 aluminium alloy were studied,with special attention paid to comparing the texture development for the symmetric and asymmetric cold rolling.Scanning electron microscopy with electron-backscatter diffraction was used to monitor the development of the microstructure in the differently deformed and additionally annealed samples.Details of the formations and transformations of individual texture components occurring during the rolling processes were observed and discussed.The average grain sizes,textures and mechanical properties were correlated and explained for the symmetric and asymmetric cold-rolled samples.The asymmetric rolling is beneficial in terms of deep drawability because it reduces the planar anisotropy of the annealed material due to the decrease of the Cube,Goss,rotated-Cube and η-fibre texture components and at the same time strengthens X1-and X2-fibre texture components which are shear texture components and improve deep drawability.During the asymmetric cold rolling,the temperature increases due to friction,triggering recrystallisation processes and leading to larger grains.It is also confirmed that asymmetric cold rolling uses less rolling force and consequently less energy to produce a final material with better formability,particularly earing.
基金supported by the National Natural Science Foundation of China(No.51905123)Major Scientific and Technological Innovation Program of Shandong Province,China(Nos.2020CXGC010303,2022ZLGX04)Key R&D Programme of Shandong Province,China(No.2022JMRH0308).
文摘An internal state variable(ISV)model was established according to the experimental results of hot plane strain compression(PSC)to predict the microstructure evolution during hot spinning of ZK61 alloy.The effects of the internal variables were considered in this ISV model,and the parameters were optimized by genetic algorithm.After validation,the ISV model was used to simulate the evolution of grain size(GS)and dynamic recrystallization(DRX)fraction during hot spinning via Abaqus and its subroutine Vumat.By comparing the simulated results with the experimental results,the application of the ISV model was proven to be reliable.Meanwhile,the strength of the thin-walled spun ZK61 tube increased from 303 to 334 MPa due to grain refinement by DRX and texture strengthening.Besides,some ultrafine grains(0.5μm)that played an important role in mechanical properties were formed due to the proliferation,movement,and entanglement of dislocations during the spinning process.
基金supported by the Key Research and Development Program of Heilongjiang (2022ZX01A01)National Natural Science Foundation of China (51975167)Natural Science Foundation of Heilongjiang Province(LH2022E080)。
文摘Rare-earth(RE) magnesium alloys have attracted lots of attention due to their excellent mechanical properties.In this work,the microstructure and mechanical properties of as-extruded 8.5Gd-4.5Y-0.8Zn-0.4Zr magnesium alloy under different solution treatment were examined with the optical microscope(OM),scanning electron microscope(SEM),high resolution transmission electron microscope(HRTEM),electron back-scattered diffraction(EBSD) and Instron testing machine.The results show that the ES12alloy(solution treatment for 12 h at 520℃) has the highest ultimate tensile strength(UTS) of 390 MPa with a fracture elongation of 24.5% at the co st of a minor drop in yielding strength(YS) compared to the asextruded alloy.During solution treatment,the block-shaped long period stacking ordered(LPSO) in asextruded alloy evolves into plate-shaped LPSO,which disperses at grain boundaries(GBs),and lamellar LPSO,which distributes in grains.The coexistence of plate-shaped and lamellar LPSO,which impedes the dislocations movement,and the activated dislocations are regarded as the primary reasons for mechanical properties improvement.Furthermore,the(11-21) <1-100> texture in as-extruded alloy transforms into the(11-20) <0001> texture in ES12 alloy.The average grain size increases from 3.45 μm in as-extruded alloy to 18.70 μm in ES12 alloy.The Schmid factors of {0001} <11-20>,{10-10} <11-20>,{10-11} <11-20>,and {11-22} <11-23> increase,which indicate that slip systems are more easily activated in plastic deformation.The dynamic recrystallization(DRX) grains fraction increase to 92.8% for ES12 alloy due to the particle-stimulated nucleation(PSN) mechanism triggered by block-shaped and plate-shaped LPSO.The freshly DRXed grains further weaken the texture,and reduce the dislocation density.All of these factors increase elongation of RE magnesium alloy.
基金supported by the Nation Key Research and Development Program of China(No.2021YFB3701100).
文摘Hot deformation with high strain rate has been paid more attention due to its high efficiency and low cost,however,the strain rate dependent dynamic recrystallization(DRX)and texture evolution in hot deformation process,which affect the formability of metals,are lack of study.In this work,the DRX behavior and texture evolution of Mg-8Gd-1Er-0.5Zr alloy hot compressed with strain rates of 0.1 s^(−1),1 s^(−1),10 s^(−1) and 50 s^(−1) are studied,and the corresponding dominant mechanisms for DRX and texture weakening are discussed.Results indicated the DRX fraction was 20%and the whole texture intensity was 16.89 MRD when the strain rate was 0.1 s^(−1),but they were 76%and 6.55 MRD,respectively,when the strain rate increased to 50 s^(−1).The increment of DRX fraction is suggested to result from the reduced DRX critical strain and the increased dislocation density as well as velocity,while the weakened whole texture is attributed to the increased DRX grains.At the low strain rate of 0.1 s^(−1),discontinuous DRX(DDRX)was the dominant,but the whole texture was controlled by the deformed grains with the preferred orientation of{0001}⊥CD,because the number of DDRX grains was limited.At the high strain rate of 50 s^(−1),continuous DRX(CDRX)and twin-induced DRX(TDRX)were promoted,and more DRX grains resulted in orientation randomization.The whole texture was mainly weakened by CDRX and TDRX grains,in which CDRX plays a major role.The results of present work are significant for understanding the hot workability of Mg-RE alloys with a high strain rate.
基金by National Natural Science Foundation of China(Nos.52271103,52334010 and 52271031)Jilin Scientific and Technological Development Program(Nos.20220301026GX,20210201115GX and 20210301041GX).
文摘Conventional rolled Mg-Al alloy sheets typically exhibit strong basal textures that remain and may even strengthen after recrystallization annealing due to the preferential growth of basal-oriented grains,resulting in poor formability at room temperature.Therefore,the knowledge of recrystallization and grain growth is critical for modifying textures of Mg-Al alloy sheets.The static recrystallization and texture evolution in a cold-rolled dilute Mg-1Al(wt.%)alloy during various annealed temperatures ranging from 300℃ to 450℃,have been investigated using the quasi in-situ electron backscatter diffraction(EBSD)method.The as-rolled Mg-1Al alloy shows a dominant basal texture,which weakens and broadens in the rolling direction(RD)during the subsequent annealing,accompanied by the formation of{1010}texture component.Particularly,the {1010} texture component is more pronounced after annealing at high temperatures.The quasi in-situ EBSD results show that recrystallized grains are mainly induced by shear bands,which exhibit a wide spectrum of orientations with c-axis tilt angles ranging 20°-45°from the normal direction(ND).Orientations of shear band-induced recrystallized grains are retained during the entire recrystallization process,resulting in a reduction in the texture intensity.Moreover,recrystallized grains belonging to the {1010}texture component grow preferentially compared to those with other orientations,which is attributed to low energy grain boundaries,especially grain boundaries with∼30°misorientation angles.Furthermore,the high temperature annealing facilitates the rapid growth of grain boundaries having a 30°misorientation angle,leading to the occurrence of distinct {1010} texture after annealing at 450℃ for 1 h.The results provide insights for texture modification of rare earth-free low-alloyed Mg alloys by controlling annealing parameters.
基金financially supported by the National Key Research and Development Program of China(No.2022YFA1205300 and No.2022YFA1205304)the Oceanic Interdisciplinary Program of Shanghai Jiao Tong University(SL2022ZD103).
文摘Monitoring minuscule mechanical signals,both in magnitude and direction,is imperative in many application scenarios,e.g.,structural health monitoring and robotic sensing systems.However,the piezoelectric sensor struggles to satisfy the requirements for directional recognition due to the limited piezoelectric coefficient matrix,and achieving sensitivity for detecting micrometer-scale deformations is also challenging.Herein,we develop a vector sensor composed of lead zirconate titanate-electronic grade glass fiber composite filaments with oriented arrangement,capable of detecting minute anisotropic deformations.The as-prepared vector sensor can identify the deformation directions even when subjected to an unprecedented nominal strain of 0.06%,thereby enabling its utility in accurately discerning the 5μm-height wrinkles in thin films and in monitoring human pulse waves.The ultra-high sensitivity is attributed to the formation of porous ferroelectret and the efficient load transfer efficiency of continuous lead zirconate titanate phase.Additionally,when integrated with machine learning techniques,the sensor’s capability to recognize multi-signals enables it to differentiate between 10 types of fine textures with 100%accuracy.The structural design in piezoelectric devices enables a more comprehensive perception of mechanical stimuli,offering a novel perspective for enhancing recognition accuracy.
基金the Deanship of Scientifc Research at King Khalid University for funding this work through large group Research Project under grant number RGP2/421/45supported via funding from Prince Sattam bin Abdulaziz University project number(PSAU/2024/R/1446)+1 种基金supported by theResearchers Supporting Project Number(UM-DSR-IG-2023-07)Almaarefa University,Riyadh,Saudi Arabia.supported by the Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(No.2021R1F1A1055408).
文摘Machine learning(ML)is increasingly applied for medical image processing with appropriate learning paradigms.These applications include analyzing images of various organs,such as the brain,lung,eye,etc.,to identify specific flaws/diseases for diagnosis.The primary concern of ML applications is the precise selection of flexible image features for pattern detection and region classification.Most of the extracted image features are irrelevant and lead to an increase in computation time.Therefore,this article uses an analytical learning paradigm to design a Congruent Feature Selection Method to select the most relevant image features.This process trains the learning paradigm using similarity and correlation-based features over different textural intensities and pixel distributions.The similarity between the pixels over the various distribution patterns with high indexes is recommended for disease diagnosis.Later,the correlation based on intensity and distribution is analyzed to improve the feature selection congruency.Therefore,the more congruent pixels are sorted in the descending order of the selection,which identifies better regions than the distribution.Now,the learning paradigm is trained using intensity and region-based similarity to maximize the chances of selection.Therefore,the probability of feature selection,regardless of the textures and medical image patterns,is improved.This process enhances the performance of ML applications for different medical image processing.The proposed method improves the accuracy,precision,and training rate by 13.19%,10.69%,and 11.06%,respectively,compared to other models for the selected dataset.The mean error and selection time is also reduced by 12.56%and 13.56%,respectively,compared to the same models and dataset.
基金supported by the project“GEF9874:Strengthening Coordinated Approaches to Reduce Invasive Alien Species(lAS)Threats to Globally Significant Agrobiodiversity and Agroecosystems in China”funding from the Excellent Talent Training Funding Project in Dongcheng District,Beijing,with project number 2024-dchrcpyzz-9.
文摘Ecological monitoring vehicles are equipped with a range of sensors and monitoring devices designed to gather data on ecological and environmental factors.These vehicles are crucial in various fields,including environmental science research,ecological and environmental monitoring projects,disaster response,and emergency management.A key method employed in these vehicles for achieving high-precision positioning is LiDAR(lightlaser detection and ranging)-Visual Simultaneous Localization and Mapping(SLAM).However,maintaining highprecision localization in complex scenarios,such as degraded environments or when dynamic objects are present,remains a significant challenge.To address this issue,we integrate both semantic and texture information from LiDAR and cameras to enhance the robustness and efficiency of data registration.Specifically,semantic information simplifies the modeling of scene elements,reducing the reliance on dense point clouds,which can be less efficient.Meanwhile,visual texture information complements LiDAR-Visual localization by providing additional contextual details.By incorporating semantic and texture details frompaired images and point clouds,we significantly improve the quality of data association,thereby increasing the success rate of localization.This approach not only enhances the operational capabilities of ecological monitoring vehicles in complex environments but also contributes to improving the overall efficiency and effectiveness of ecological monitoring and environmental protection efforts.
基金Supported by the National Natural Science Foundation of China,No.81560278the Health Commission of Guangxi Zhuang Autonomous Region,No.Z20200953,No.G201903023,and No.Z-A20221157Scientific Research and Technology Development Project of Nanning,No.20213122.
文摘BACKGROUND Microvascular invasion(MVI)is a significant risk factor for recurrence and metastasis following hepatocellular carcinoma(HCC)surgery.Currently,there is a paucity of preoperative evaluation approaches for MVI.AIM To investigate the predictive value of texture features and radiological signs based on multiparametric magnetic resonance imaging in the non-invasive preoperative prediction of MVI in HCC.METHODS Clinical data from 97 HCC patients were retrospectively collected from January 2019 to July 2022 at our hospital.Patients were classified into two groups:MVI-positive(n=57)and MVI-negative(n=40),based on postoperative pathological results.The correlation between relevant radiological signs and MVI status was analyzed.MaZda4.6 software and the mutual information method were employed to identify the top 10 dominant texture features,which were combined with radiological signs to construct artificial neural network(ANN)models for MVI prediction.The predictive performance of the ANN models was evaluated using area under the curve,sensitivity,and specificity.ANN models with relatively high predictive performance were screened using the DeLong test,and the regression model of multilayer feedforward ANN with backpropagation and error backpropagation learning method was used to evaluate the models’stability.RESULTS The absence of a pseudocapsule,an incomplete pseudocapsule,and the presence of tumor blood vessels were identified as independent predictors of HCC MVI.The ANN model constructed using the dominant features of the combined group(pseudocapsule status+tumor blood vessels+arterial phase+venous phase)demonstrated the best predictive performance for MVI status and was found to be automated,highly operable,and very stable.CONCLUSION The ANN model constructed using the dominant features of the combined group can be recommended as a noninvasive method for preoperative prediction of HCC MVI status.
基金Inner Mongolia Natural Science Foundation Project(2020LH05028)。
文摘Impact of texture type on the magnetic properties of ultrahigh density perpendicular magnetic recording media L1_(0)-FePt thin film was investigated,so were the texture formation and evolution mechanism.Reuss,Voigt,and Hill models were used to determine the anisotropic elastic modulus of L1_(0)-FePt thin film with fiber texture.Then,the elastic strain energies of thin films under various stress conditions were calculated.Results reveal that the stress condition has a significant influence on the fiber texture evolution.When the L1_(0)-FePt thin film is subjected to compressive in-plane strain prior to ordering phase transformation,the formation of{100}fiber texture is promoted.On the contrary,the ordering phase transformation under tensile in-plane strain promotes the{001}fiber texture formation.
基金Project(51975169)supported by the National Natural Science Foundation of ChinaProject(LH2022E085)supported by the Natural Science Foundation of Heilongjiang Province,China。
文摘Efficient tool condition monitoring techniques help to realize intelligent management of tool life and reduce tool usage costs.In this paper,the influence of different wear degrees of ball-end milling cutters on the texture shape of machining tool marks is investigated,and a method is proposed for predicting the wear state(including the position and degree of tool wear)of ball-end milling cutters based on entropy measurement of tool mark texture images.Firstly,data samples are prepared through wear experiments,and the change law of the tool mark texture shape with the tool wear state is analyzed.Then,a two-dimensional sample entropy algorithm is developed to quantify the texture morphology.Finally,the processing parameters and tool attitude are integrated into the prediction process to predict the wear value and wear position of the ball end milling cutter.After testing,the correlation between the predicted value and the standard value of the proposed tool condition monitoring method reaches 95.32%,and the accuracy reaches 82.73%,indicating that the proposed method meets the requirement of tool condition monitoring.
基金supported by the PHC-Tassili program No.24MDU114。
文摘The difference in the microstructure,texture in the stir zone(SZ)of the AZ31(Mg-3 Al-1 Zn,wt.%)alloy after friction stir welding(FSW)and subsequent annealing at 400℃for 1 h was characterized by scanning electron microscopy(SEM)with electron backscatter diffraction(EBSD)measurements at the surface and core regions.The findings indicate that FSW produced grain refinement where the mean grain size decreases from 19μm(base metal)to 5.1 and 3.5μm at the surface and core regions,respectively.The c-axis of the grains at the surface region was aligned with the normal direction(<0001>//ND)due to the additional strain of the tool shoulder.In contrast,the core region shows a typical shear texture,where the c-axis tends to be oriented parallel to the welding direction(<0001>//WD).The Vickers microhardness mapping across the SZ revealed that the core region was soften than the surface region due to the dynamic recrystallization and texture weakening.The microstructure of the SZ remains principally deformed after annealing treatment except for the development of massive Mg_(17)Al_(12)precipitates and the abnormal grain growth of a few grains with<11-20>//WD orientation at the upper side of the surface region.The c-axis of the grains at the surface region was tilted about 10°toward WD,while an inclined<0001>//WD orientation about 30°from WD was developed at the core region.Consequently,the distribution of microhardness values across the SZ was more heterogeneous than the FSW sample.The results were discussed in the light of grain boundary misorientation,dislocation density and the pinning effect of Mg_(17)Al_(12)precipitates.Additionally,Schmid factor analysis was used to examine the activation of the basal slip mode to characterize the associated mechanical response.
基金funded by the National Natural Science Foundation of China(Grant No.52175028).
文摘Accurate and robust navigation in complex surgical environments is crucial for bronchoscopic surgeries.This study purposes a bronchoscopic lumen feature matching network(BLFM-Net)based on deep learning to address the challenges of image noise,anatomical complexity,and the stringent real-time requirements.The BLFM-Net enhances bronchoscopic image processing by integrating several functional modules.The FFA-Net preprocessing module mitigates image fogging and improves visual clarity for subsequent processing.The feature extraction module derives multi-dimensional features,such as centroids,area,and shape descriptors,from dehazed images.The Faster RCNN Object detection module detects bronchial regions of interest and generates bounding boxes to localize key areas.The feature matching module accelerates the process by combining detection boxes,extracted features,and a KD-Tree(K-Dimensional Tree)-based algorithm,ensuring efficient and accurate regional feature associations.The BLFM-Net was evaluated on 5212 bronchoscopic images,demonstrating superior performance compared to traditional and other deep learning-based image matching methods.It achieved real-time matching with an average frame time of 6 ms,with a matching accuracy of over 96%.The method remained robust under challenging conditions including frame dropping(0,5,10,20),shadowed regions,and variable lighting,maintaining accuracy of above 94%even with the frame dropping of 20.This study presents BLFM-Net,a deep learning-based matching network designed to enhance and match bronchial features in bronchoscopic images.The BLFM-Net shows improved accuracy,real-time performance,and reliability,making a valuable tool for bronchoscopic surgeries.
基金Tral Science Foundation of China(Nos.52271103,52334010and 52271031)Partial financial support came from JilinScientific and Technological Development Program(No.20220301026GX)Program for the Central UniversityYouth Innovation Team。
文摘In this work,a good balance of strength and ductility(a yield strength of 185 MPa and a uniform elongation of 20%)has been obtained in a dilute Mg-1.8Zn-0.3Y-0.3Ca-0.3Zr(wt.%)alloy using hard plate rolling(HPR)followed by annealing,with a low anisotropy in mechanical properties.More importantly,the HPR-annealed alloy shows an excellent formability at the same time,i.e.,the index Erichsen(I.E.)value reaches 7.9 mm(the Erichsen cupping test)at room temperature,which is higher compared with the Mg-1.8Zn-0.3Y-0.3Ca0.3Zr alloy produced by conventional multi-pass rolling(CR)followed by annealing.The excellent synergy of strength and formability of the HPR-annealed alloy is mainly attributed to a weak elliptical ring texture,as well as finer and denser Zn_(2)Zr_(3)precipitates.The formation of weak elliptical ring texture is related to the preferential co-segregation of Zn and Ca elements at boundaries of basal grains with smal misorientation angles during annealing,which inhibits the growth of basal grains and promotes the preferential growth of non-basal grains At the same time,in comparison with the CR-annealed alloy,the HPR-annealed alloy contains finer and denser Zn_(2)Zr_(3)precipitates that ar less likely to become sources of cracks,leading to the higher strength and formability of the HPR-annealed alloy.The results in this work can provide reference for the development of high strength Mg alloy sheets with excellent room temperature formability,which also shed light on mitigating planar anisotropy in mechanical properties for Mg alloy sheets.
文摘Panoramic images, offering a 360-degree view, are essential in virtual reality(VR) and augmented reality(AR), enhancing realism with high-quality textures. However, acquiring complete and high-quality panoramic textures is challenging. This paper introduces a method using generative adversarial networks(GANs) and the contrastive language-image pretraining(CLIP) model to restore and control texture in panoramic images. The GAN model captures complex structures and maintains consistency, while CLIP enables fine-grained texture control via semantic text-image associations. GAN inversion optimizes latent codes for precise texture details. The resulting low dynamic range(LDR) images are converted to high dynamic range(HDR) using the Blender engine for seamless texture blending. Experimental results demonstrate the effectiveness and flexibility of this method in panoramic texture restoration and generation.
基金financially supported by the Cultivation Project of CQUT for Research and Innovation Group(No.2023TDZ006)the Graduate Student Innovation Program of CQUT(No.CYS23648)the Postdoctoral Science Foundation of China(No.2021M690174)。
文摘A high-purity Ti sheet with dense preexisting twins(introduced by 10%cold rolling)was subjected to isochronal annealing at 500–800°C for 1 h and isothermal annealing at 600°C for 0.17–100 h,respectively.By mainly utilizing electron backscatter diffraction(EBSD)and electron channel contrast(ECC)imaging techniques,the microstructure and texture evolution during the isochronal and isothermal annealing were investigated systematically.Results show that recrystallization nuclei appear in the specimen annealed at 600°C for 1 h.In contrast,recrystallization cannot be initiated for those annealed at lower temperatures or for a shorter time.With the increase in temperature or time,the fraction of the recrystallized structure increases with gradual grain coarsening.Nearly complete recrystallization is reached after 800°C-1 h or 600°C-100 h annealing.Due to the distribution heterogeneity of microstructure and stored energy induced by the dense preexisting twins,recrystallization nucleation preferentially occurs in some specific regions(twin-twin or twin-grain boundary junctions).Then,they selectively consume twin lamellar structures,leading to non-uniform grain growth.It is demonstrated that the recrystallization nucleation is dominated by the strain-induced boundary migration mechanism,allowing scattered texture components corresponding to the twin lamellar structures to be gradually encroached by those untwinned structures with the initial bimodal basal texture(BBT).Eventually,a strong BBT is always obtained after sufficient recrystallization.
基金financially supported by the National Natural Science Foundation of China(No.52475341)the Natural Science Foundation of Heilongjiang Province(No.JQ2022E004)。
文摘Given the limitations of traditional hot extrusion methods in improving the microstructure and mechanical properties of magnesium(Mg)alloys,this paper attempts to treat AZ31 Mg alloy billet by pre-upsetting continuous variable cross-section direct extrusion(U-CVCDE).The effects of dynamic recrystallization behavior and slip system activity on texture evolution and mechanical properties of CVCDE Mg alloys with different pre-upsetting amounts were systematically analyzed.The results indicate that the introduction of the pre-upsetting process promotes dynamic recrystallization during the CVCDE process.The recrystallization proportion shows a trend of first rising and then decreasing with the increase of the pre-upsetting amount.Among them,the proportion of recrystallization grains in the U2-CVCDE-formed structural parts is as high as 88.3%.The average grain sizes of U1-CVCDE,U2-CVCDE,and U3-CVCDE were 6.01μm,4.90μm,and10.45μm,respectively.In addition,following U-CVCDE,the pyramidal slip of each forming component consistently maintains a high level of activation and opening and dominates,making more grains deflect in the axial extrusion direction of C to varying degrees,which is conducive to the uniform distribution of stress in more grains during plastic deformation.The synergistic effect of dynamic recrystallization behavior and the high activity of the pyramidal slip system significantly weakened the(0001)basal texture strength,and the maximum basal texture strength showed a gradually decreasing trend,among which the base surface texture strength of U3-CVCDE formed parts was only 9.9.The U-CVCDE process is employed to achieve deep modification of Mg alloy,and excellent comprehensive mechanical properties are obtained;among them,the yield and tensile strength of U2-CVCDE are as high as 243.4 MPa and 317.5 MPa,respectively,and the elongation after breaking is up to 21.3%.This study introduces a practical new idea for investigating the extrusion forming technology of high-performance Mg alloys.
基金Project(52405369) supported by National Natural Science Foundation of ChinaProject(BK20210891) supported by the Natural Science Foundation of Jiangsu Province,ChinaProject(BX2022030) supported by the Special Project of Introducing Foreign Talents of Jiangsu Province,China。
文摘Cold-rolling was conducted on AZ31 magnesium alloy with fine and coarse grains to produce plates with high density of shear bands and{101^(-)1}twins,respectively.Then,these two kinds of plates are subjected to isothermal annealing to reveal the effect of shear bands and{101^(-)1}twins on recrystallization behavior.During annealing,static recrystallization occurs firstly in shear band zones and{101^(-)1}twin zones,which has different effect on texture and mechanical properties.With the increase of annealing temperature,strong basal texture remains in annealed SG-17%while the basal texture is weakened gradually in annealed LG-15%.Recrystallized grains from twin zones have a random orientation which is responsible for the weakened basal texture in annealed LG-15%.In addition,microhardness decreases gradually with the prolonged annealing time due to static recrystallization.LG-15%has a lower recrystallization activation energy because{101^(-)1}twins are in favor of the nucleation and growth of recrystallized grains.After 500℃annealing,the yield strength decreases significantly with a significant improvement in failure strain.The annealed LG-15%has a much higher compressive strain than the annealed SG-17%due to texture weakening effect.
