Microstructure and texture in 6016 aluminum alloy during hot compression were researched with a uni- axial compression experiment. Through the electron back- scattered diffraction （EBSD） and X-ray diffraction （XRD...Microstructure and texture in 6016 aluminum alloy during hot compression were researched with a uni- axial compression experiment. Through the electron back- scattered diffraction （EBSD） and X-ray diffraction （XRD） analysis technology, it is shown that the subgrain nucle- ation and recrystallization occur in 6016 aluminum alloy during hot compressing, and strong rolling textures such as （110） fiber texture, Brass, S, and Goss form. With the deformation passes increasing, （110） fiber texture, Brass and S are enhanced. In the heat preservation stage after deformation, recrystallization continues until heat preser- vation for 60 s, and a duplex microstructure of deformation and recrystallization grains is built. At the beginning of heat preservation, recrystallization grains with the Goss texture and random orientation are formed in original grains with S or Brass texture, which makes the volume fraction of S and Brass texture decrease. Then, the complex grain growth process makes the volume fraction of Brass, S, and Goss texture increase, while that of random orien- tation decrease.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
Interfacial evolution and bonding mechanism of reduced activation ferritic/martensitic(RAFM)steel were systematically investigated through a series of hot compression tests conducted at various strains(0.15-0.8),strai...Interfacial evolution and bonding mechanism of reduced activation ferritic/martensitic(RAFM)steel were systematically investigated through a series of hot compression tests conducted at various strains(0.15-0.8),strain rates(0.001-1 s^(-1)),and temperatures(950-1050℃).Interfacial microstructural analysis revealed that plastic deformation of surface asperities effectively removes interfacial voids,and the evolution of dynamic recrystallization(DRX)aids in achieving a joint characterized by homogeneously refined microstructure and adequate interfacial grain boundary(IGB)migration.Electron backscattered diffraction analysis demonstrated that the continuous dynamic recrystallization,characterized by progressive subgrain rotation,is the prevailing DRX nucleation mechanism in RAFM steel during hot compression bonding.During DRX evolution,emerging DRX grains in the interfacial region expand into adjacent areas,transforming T-type triple junction grain boundaries into equal form,and resulting in a serrated and intricate interface.Elevated temperatures and strains,coupled with reduced strain rates,augment DRX grain nucleation and IGB migration,thus enhancing RAFM joint quality with regard to the interface bonding ratio and the interface migration ratio.展开更多
Objective:To explore the application of external application of Traditional Chinese Medicine(TCM)hot compress package combined with Kinesio Taping in postoperative nursing of total knee arthroplasty.Methods:90 patient...Objective:To explore the application of external application of Traditional Chinese Medicine(TCM)hot compress package combined with Kinesio Taping in postoperative nursing of total knee arthroplasty.Methods:90 patients with severe knee osteoarthritis who underwent total knee arthroplasty in our department from January to December 2022 were randomly divided into two groups using a random number table method:one group was named the conventional group(n=45),which received the standard orthopedic nursing process throughout,including basic pain management,incision care,and functional exercise guidance;the other group was defined as the experimental group(n=45),which,in addition to the conventional nursing framework,incorporated the local transdermal drug delivery technique of TCM hot compress package and the biomechanical correction scheme of Kinesio Taping for collaborative intervention.Finally,the differences in postoperative resting/active pain scores(VAS)of the affected limb and satisfaction with nursing services between the two groups were compared using quantitative assessment tools.Results:The satisfaction with nursing care in the conventional group was significantly lower than that in the experimental group(P<0.05);the VAS score after nursing in the conventional group was significantly higher than that in the experimental group(P<0.05).Conclusion:The application of external application of TCM hot compress package combined with Kinesio Taping in postoperative nursing of total knee arthroplasty has a definite effect,reducing pain and improving patient satisfaction with nursing services.展开更多
A Mg−13Gd−4Y−2Zn−0.5Zr(wt.%)alloy was selected as the experimental material.After preheating,initial microstructures with different long-period stacking ordered(LPSO)phase andβ'phase distributions were obtained,a...A Mg−13Gd−4Y−2Zn−0.5Zr(wt.%)alloy was selected as the experimental material.After preheating,initial microstructures with different long-period stacking ordered(LPSO)phase andβ'phase distributions were obtained,and hot compression experiments were conducted.The effects of secondary phases on microstructure and dynamic recrystallization(DRX)behavior were investigated.The results revealed that the average grain size decreased from 70.93 to 31.53μm,and the DRX volume fraction increased from 20.3%to 40.1%after the pre-annealing treatment.The average grain size of Sample S0(pre-aging)decreased to 39.29μm,and the DRX volume fraction increased by 79.8%,whereas the average grain size of Samples S1−S7(pre-annealing+aging)slightly increased,and the DRX volume fraction slightly decreased.With increasing pre-annealing time,the width of the lamellar LPSO phase increased,which generated less dynamic precipitation during deformation and weakened the pinning effect.The DRX mechanism transformed from continuous dynamic recrystallization(CDRX,pre-homogenization sample)to particle-stimulated nucleation(PSN)+discontinuous dynamic recrystallization(DDRX,pre-annealing sample).After the pre-aging treatment,the reticular structure effectively pinned the dislocations and delayed the nucleation and growth of DRX grains.The DRX mechanism changed from the original CDRX+PSN(pre-aging sample)to DDRX(pre-annealing+aging sample).展开更多
Plastometric experiments,supplemented with numerical simulations using the finite element method(FEM),can be advantageously used to characterize the deformation behavior of metallic materials.The accuracy of such simu...Plastometric experiments,supplemented with numerical simulations using the finite element method(FEM),can be advantageously used to characterize the deformation behavior of metallic materials.The accuracy of such simulations predicting deformation behaviors of materials is,however,primarily affected by the applied rheology law.The presented study focuses on the characterization of the deformation behavior of AISI 1045 type carbon steel,widely used e.g.,in automotive and power engineering,under extreme conditions(i.e.,high temperatures,strain rates).The study consists of two main parts:experimentally analyzing the flow stress development of the steel under different thermomechanical conditions via uniaxial hot compression tests and establishing the rheology law via numerical simulations implementing the experimentally acquired flow stress curves.The numerical simulations then not only serve to establish the rheology law but also to verify the reliability of the selected experimental process.The results of the numerical simulations showed that the established rheology law characterizes the behavior of the investigated steel with sufficient accuracy also at high temperatures and/or strain rates,and can,therefore,be used for practical purposes.Last but not least,supplementary microstructure analyses performed for the samples subjected to the highest deformation temperature provided a deeper insight into the effects of the applied(extreme)thermomechanical conditions on the behavior of the investigated steel.展开更多
An additional hot compression process was applied to a dilute Mg−Mn−Zn alloy post-extrusion.The alloy was extruded at 150℃ with an extrusion ratio of 15:1 and subsequently hot-compressed at 180℃ with a true strain o...An additional hot compression process was applied to a dilute Mg−Mn−Zn alloy post-extrusion.The alloy was extruded at 150℃ with an extrusion ratio of 15:1 and subsequently hot-compressed at 180℃ with a true strain of 0.9 along the extrusion direction.The microstructure,mechanical properties and thermal conductivity of as-extruded and as-hot compressed Mg−Mn−Zn alloys were investigated using optical microscopy,scanning electron microscopy,electron backscattering diffraction,and transmission electron microscopy.The aim was to concurrently enhance both strength and thermal conductivity by fostering uniform and refined microstructures while mitigating basal texture intensity.Substantial improvements were observed in yield strength(YS),ultimate tensile strength(UTS),and elongation(EL),with increase of 77%,53% and 10%,respectively.Additionally,thermal conductivity demonstrated a notable enhancement,rising from 111 to 125 W/(m·K).The underlying mechanism driving these improvements through the supplementary hot compression step was thoroughly elucidated.This study presents a promising pathway for the advancement of Mg alloys characterized by superior thermal and mechanical properties.展开更多
An innovative method of hot compression bonding is proposed in this work for the joining of 9Cr oxide dispersion strengthened(ODS)alloy and 9Cr reduced-activation ferritic/martensitic(RAFM)alloy.The microstructural ev...An innovative method of hot compression bonding is proposed in this work for the joining of 9Cr oxide dispersion strengthened(ODS)alloy and 9Cr reduced-activation ferritic/martensitic(RAFM)alloy.The microstructural evolution of the bonding interface was investigated by scanning electron microscopy(SEM),electron back-scattered diffraction(EBSD),and transmission electron microscopy(TEM).The results verify that the pinning effect of nano-oxides particles(NPs)in 9Cr ODS alloy significantly enhances its dynamic recrystallization(DRX)temperature and deformation resistance.Continuous DRX(CDRX)first occurred on the 9Cr RAFM alloy side,and the areas near the bonding interface were composed of recrystallized grains.With increasing strain,CDRX also showed up on the 9Cr ODS alloy side.Inevitable slight oxidation occurred at the bonding interface during the hot compression bonding(HCB)process,and the interfacial oxides transformed from initial coarse CrO to TiO and finally to Y-Ti-O nanoparticles with sizes comparable to pre-existing NPs dispersed in the 9Cr ODS alloy matrix.It is believed that interfacial oxide transformation and grain structure consistency contributed to the excellent interface healing of the two dissimilar alloy pieces.The effectiveness of the bonding was tested by tensile tests and fractography analysis,revealing that ideal metallurgical bonding could be achieved under a controlled strain level of 10%at 800℃ followed by soaking at 1000℃ for 4 h.展开更多
Hot deformation behavior of extrusion preform of the spray-formed Al-9.0Mg-0.5Mn-0.1Ti alloy was studied using hot compression tests over deformation temperature range of 300-450 ℃ and strain rate range of 0.01...Hot deformation behavior of extrusion preform of the spray-formed Al-9.0Mg-0.5Mn-0.1Ti alloy was studied using hot compression tests over deformation temperature range of 300-450 ℃ and strain rate range of 0.01-10 s-1. On the basis of experiments and dynamic material model, 2D processing maps and 3D power dissipation maps were developed for identification of exact instability regions and optimization of hot processing parameters. The experimental results indicated that the efficiency factor of energy dissipate （η） lowered to the minimum value when the deformation conditions located at the strain of 0.4, temperature of 300 ° C and strain rate of 1 s-1. The softening mechanism was dynamic recovery, the grain shape was mainly flat, and the portion of high angle grain boundary （〉15°） was 34%. While increasing the deformation temperature to 400 ° C and decreasing the strain rate to 0.1 s-1, a maximum value of η was obtained. It can be found that the main softening mechanism was dynamic recrystallization, the structures were completely recrystallized, and the portion of high angle grain boundary accounted for 86.5%. According to 2D processing maps and 3D power dissipation maps, the optimum processing conditions for the extrusion preform of the spray-formed Al？9.0Mg？0.5Mn？0.1Ti alloy were in the deformation temperature range of 340-450 ° C and the strain rate range of 0.01-0.1 s-1 with the power dissipation efficiency range of 38%？43%.展开更多
Background: Although a number of studies have reported that the hot and humid compress from traditional Chinese medicine (TCM) is effective in treating lumbar disc herniation (LDH) with qi stagnation and blood stasis,...Background: Although a number of studies have reported that the hot and humid compress from traditional Chinese medicine (TCM) is effective in treating lumbar disc herniation (LDH) with qi stagnation and blood stasis, clinical evidence is limited. Objective: The purpose of this study is to provide high-quality evidence to support the effectiveness of the traditional Chinese hot and humid compress in the treatment of LDH with qi stagnation and blood stasis. Methods: From October 2021 to November 2023, 86 patients with LDH of qi stagnation and blood stasis type were recruited in our hospital and divided into a control (n = 43) and an observation group (n = 43) according to the random number table method. The control group was given routine clinical treatment, and the observation group was treated with the hot and humid compress therapy for two weeks. The visual analogue scale (VAS) score, Japanese Orthopaedic Association (JOA) score, TCM syndrome score, serum interleukin-6 (IL-6), serum interleukin-1β (IL-1β), and tumor necrosis factor-α (TNF-α) were observed and compared between the two groups before and after treatment, and the clinical efficacy of the two groups was evaluated. Results: After treatment, the VAS score, TCM symptom score, and serum IL-6, IL-1β, and TNF-α levels decreased in both groups (P P P P P Conclusions: The hot and humid compress of traditional Chinese medicine can effectively relieve pain, restore lumbar function, improve TCM syndromes, reduce the level of inflammatory factors, and have a curative effect in treating LDH.展开更多
The high-temperature deformation behavior of Cu-Ni-Si-P alloy was investigated by using the hot compression test in the temperature range of 600-800 ℃ and strain rate of 0.01-5 s-1. The hot deformation activation ene...The high-temperature deformation behavior of Cu-Ni-Si-P alloy was investigated by using the hot compression test in the temperature range of 600-800 ℃ and strain rate of 0.01-5 s-1. The hot deformation activation energy, Q, was calculated and the hot compression constitutive equation was established. The processing maps of the alloy were constructed based on the experiment data and the forging process parameters were then optimized based on the generated maps for forging process determination. The flow behavior and the microstructural mechanism of the alloy were studied. The flow stress of the Cu-Ni-Si-P alloy increases with increasing strain rate and decreasing deformation temperature, and the dynamic recrystallization temperature of alloy is around 700 ℃. The hot deformation activation energy for dynamic recrystallization is determined as 485.6 kJ/mol. The processing maps for the alloy obtained at strains of 0.3 and 0.5 were used to predict the instability regimes occurring at the strain rate more than 1 s-1 and low temperature （〈650 ℃）. The optimum range for the alloy hot deformation processing in the safe domain obtained from the processing map is 750-800 ℃ at the strain rate of 0.01-0.1 s i The characteristic microstructures predicted from the processing map agree well with the results of microstructural observations.展开更多
Hot compression test of a novel nickel-free white alloy Cu?12Mn?15Zn?1.5Al?0.3Ti?0.14B?0.1Ce (mass fraction, %) was conducted on a Gleeble?1500 machine in the temperature range of 600?800 °C and the strain rate r...Hot compression test of a novel nickel-free white alloy Cu?12Mn?15Zn?1.5Al?0.3Ti?0.14B?0.1Ce (mass fraction, %) was conducted on a Gleeble?1500 machine in the temperature range of 600?800 °C and the strain rate range of 0.01?10 s?1. The constitutive equation and hot processing map of the alloy were built up according to its hot deformation behavior and hot working characteristics. The deformation activation energy of the alloy is 203.005 kJ/mol. An instability region appears in the hot deformation temperature of 600?700 °C and the strain rate range of 0.32?10 s?1 when the true strain of the alloy is up to 0.7. Under the optimal hot deformation condition of 800 °C and 10 s?1 the prepared specimen has good surface quality and interior structure. The designed nickel-free alloy has very similar white chromaticity with the traditional white copper alloy (Cu?15Ni?24Zn?1.5Pb), and the color difference between them is less than 1.5, which can hardly be distinguished by human eyes.展开更多
The hot deformation behavior of a novel imitation-gold copper alloy was investigated with Gleeble-1500 thermo-mechanical simulator in the temperature range of 650-770 °C and strain rate range of 0.001-1.0 s-1. Th...The hot deformation behavior of a novel imitation-gold copper alloy was investigated with Gleeble-1500 thermo-mechanical simulator in the temperature range of 650-770 °C and strain rate range of 0.001-1.0 s-1. The hot deformation constitutive equation was established and the thermal activation energy was obtained to be 249.60 kJ/mol. The processing map at a strain of 1.2 was developed. And there are two optimal regions in processing map, namely 650-680 °C, 0.001-0.01 s-1 and 740-770 °C, 0.01-0.1 s-1. Optical microscopy was employed to investigate the microstructure evolution of the alloy in the process of deformation. Recrystallized grains and twin crystals were found in microstructures of the hot deformed alloy.展开更多
The high temperature deformation behaviors of α＋β type titanium alloy TC11 （Ti-6.5Al-3.5Mo-1.5Zr-0.3Si） with coarse lamellar starting microstructure were investigated based on the hot compression tests in the tem...The high temperature deformation behaviors of α＋β type titanium alloy TC11 （Ti-6.5Al-3.5Mo-1.5Zr-0.3Si） with coarse lamellar starting microstructure were investigated based on the hot compression tests in the temperature range of 950-1100 ℃ and the strain rate range of 0.001-10 s-1. The processing maps at different strains were then constructed based on the dynamic materials model, and the hot compression process parameters and deformation mechanism were optimized and analyzed, respectively. The results show that the processing maps exhibit two domains with a high efficiency of power dissipation and a flow instability domain with a less efficiency of power dissipation. The types of domains were characterized by convergence and divergence of the efficiency of power dissipation, respectively. The convergent domain in a＋fl phase field is at the temperature of 950-990 ℃ and the strain rate of 0.001-0.01 s^-1, which correspond to a better hot compression process window of α＋β phase field. The peak of efficiency of power dissipation in α＋β phase field is at 950 ℃ and 0.001 s 1, which correspond to the best hot compression process parameters of α＋β phase field. The convergent domain in β phase field is at the temperature of 1020-1080 ℃ and the strain rate of 0.001-0.1 s^-l, which correspond to a better hot compression process window of β phase field. The peak of efficiency of power dissipation in ℃ phase field occurs at 1050 ℃ over the strain rates from 0.001 s^-1 to 0.01 s^-1, which correspond to the best hot compression process parameters of ,8 phase field. The divergence domain occurs at the strain rates above 0.5 s^-1 and in all the tested temperature range, which correspond to flow instability that is manifested as flow localization and indicated by the flow softening phenomenon in stress-- strain curves. The deformation mechanisms of the optimized hot compression process windows in a＋β and β phase fields are identified to be spheroidizing and dynamic recrystallizing controlled by self-diffusion mechanism, respectively. The microstructure observation of the deformed specimens in different domains matches very well with the optimized results.展开更多
The compressive deformation behavior of as-quenched 7005 aluminum alloy was investigated at the temperature ranging from 250 °C to 450 °C and strain rate ranging from 0.0005 s-1 to 0.5 s^-1 on Gleeble-1500 t...The compressive deformation behavior of as-quenched 7005 aluminum alloy was investigated at the temperature ranging from 250 °C to 450 °C and strain rate ranging from 0.0005 s-1 to 0.5 s^-1 on Gleeble-1500 thermal-simulation machine. Experimental results show that the flow stress of as-quenched 7005 alloy is affected by both deformation temperature and strain rate, which can be represented by a Zener-Hollomon parameter in an exponent-type equation. By comparing the calculated flow stress and the measured flow stress, the results show that the calculated flow stress agrees well with the experimental result. Based on a dynamic material model, the processing maps were constructed for the strains of 0.1, 0.3 and 0.5. The maps and microstructural examination revealed that the optimum hot working domain is 270-340 °C, 0.05-0.5 s^-1 with the reasonable dynamic recrystallization. The instability domain exhibits adiabatic shear bands and flow localization, which should be avoided during hot working in order to obtain satisfactory properties.展开更多
The AA7150 aluminum alloy was compressed to various strains at strain rate of 10 s（-1） and temperatures of 300 °C and 450 °C, respectively. Flow stress behavior, substructure evolution, morphology and spat...The AA7150 aluminum alloy was compressed to various strains at strain rate of 10 s（-1） and temperatures of 300 °C and 450 °C, respectively. Flow stress behavior, substructure evolution, morphology and spatial distribution of precipitates were studied based on differential scanning calorimetry analysis and transmission electron microscope observation. The results showed that dynamic flow softening occurs during hot deformation. The main softening mechanism could be concluded as dynamic recovery at 300 °C and continuous dynamic recrystallization at 450 °C. The clear heterogeneous spatial distributions of precipitates are found during deformation and enhanced with increased strain. Higher contents of Cu in T phases are found at 450 °C than at 300 °C, which present a transformation process from T phases to S phases as well. The associated evidence of dynamic precipitation on dislocations and particle-stimulated nucleation, as well as the detailed microstructural inherited relationship and morphological texture（particles preferred orientation） were characterized.展开更多
The hot compression behavior of a wrought Mg-6Zn-1Al-0.3Mn magnesium alloy was investigated using Gleeble test at 200-400 °C with strain rates ranging from 0.01 to 7 s-1. The true stress-strain curves show that t...The hot compression behavior of a wrought Mg-6Zn-1Al-0.3Mn magnesium alloy was investigated using Gleeble test at 200-400 °C with strain rates ranging from 0.01 to 7 s-1. The true stress-strain curves show that the hot deformation behavior significantly depends on the deformation temperature and strain rate. The calculated hot deformation activation energy Q is 166 kJ/mol with a stress exponent n=5.99, and the constitutive equation is deduced to be ε＆ =3.16×1013[sinh（0.010σ）]5.99exp [-1.66×105/（RT）]· Deformation microstructure shows that the incompletely dynamically recrystallized grains can be found at grain boundaries and twins with the strain rates ranging from 0.01 to 1 s^-1 at 250 °C, and completely dynamic recrystallization occurs when the temperature is 350 °C or above during hot compression, the size of recrystallized grains decreases with the increment of the strain rate at the same temperature. The relatively suitable deformation condition is considered temperature 330-400 °C and strain rate of 0.01-0.03 s-1, and temperature of 350 °C and strain rate of 1 s-1.展开更多
Hot compression tests were conducted on a homogenized Mg-7Gd-4Y-1Nd-0.5Zr alloy at 450 ℃ and a strain rate of 2 s-1. Dynamic recrystallization （DRX） mechanisms were investigated by optical microscope （OM）, scanni...Hot compression tests were conducted on a homogenized Mg-7Gd-4Y-1Nd-0.5Zr alloy at 450 ℃ and a strain rate of 2 s-1. Dynamic recrystallization （DRX） mechanisms were investigated by optical microscope （OM）, scanning electron microscope （SEM） and transmission electron microscope （TEM） systematically. The crystallographic orientation information is obtained through electron back-scattering diffraction （EBSD）. The result shows that the flow stress firstly reaches a peak rapidly followed by declining to a valley, and then increases gradually again when the alloy is compressed to a strain of-1.88. DRX related to {10]2} tensile twins is extensively observed at small strains, resulting in an evident grain refinement. DRX grains first nucleate along the edges of twin boundaries with about 30~ （0001） off the twin parents. While at large strains, conventional continuous DRX （CDRX） is frequently identified by the formation of small DRX grains along the original grain boundaries and the continuously increasing misorientation from the centre of large original grains to the grain boundaries. Evidence of particle-stimulated nucleation （PSN） is also observed in the present alloy.展开更多
TA2 pure titanium was chosen to research the interaction among deformation, recrystallization and phase transformation during hot compression. The samples were hot compressed by thermal simulation method with differen...TA2 pure titanium was chosen to research the interaction among deformation, recrystallization and phase transformation during hot compression. The samples were hot compressed by thermal simulation method with different processing parameters. Variant selection induced by stress during cooling after compression was found. The prismatical texture component which featured that the [0001] direction perpendicular to the compressing direction produced preferentially under the compressing stress. As a result, the transformedα phase possesses strong prismatical texture which is different with the basal texture of compressed αphase. The minimum elastic strain energy is demonstrated to be the main reason that causes the variant selection. Dynamic recrystallization behavior and microstructure evolution during hot compression were also studied.展开更多
The hot deformation behavior of Ti-3.0Al-3.7Cr-2.0Fe-0.1B (TACFB) titanium alloy was investigated using a Gleeble-1500D thermal simulator in the temperature range of 800-950 °C, at constant strain rate from 0.01 ...The hot deformation behavior of Ti-3.0Al-3.7Cr-2.0Fe-0.1B (TACFB) titanium alloy was investigated using a Gleeble-1500D thermal simulator in the temperature range of 800-950 °C, at constant strain rate from 0.01 s-1 to 10 s-1 and with height reduction of 70%. Flow stress and microstructure evolution during hot compression of TACFB alloy were investigated. The processing map of TACFB alloy was obtained. The results indicate that the hot deformation behavior of TACFB alloy is sensitive to the deformation temperature and strain rate. The peak flow stress decreases with increasing the test temperature and decreasing the strain rate. The constitutive relationship of TACFB alloy was obtained on the base of Arrhenius equations. When the strain rates are higher than 1.0 s-1, the dynamic recrystallization occurs, and the higher the strain rates are, the more the recrystallization is.展开更多
基金financially supported by the Original Program of Chongqing Foundational and Frontier Research Plan(No.cstc2013jcyjA70015)the Science and Technology Research Program of Education Council of Chongqing(No.KJ080407)
文摘Microstructure and texture in 6016 aluminum alloy during hot compression were researched with a uni- axial compression experiment. Through the electron back- scattered diffraction （EBSD） and X-ray diffraction （XRD） analysis technology, it is shown that the subgrain nucle- ation and recrystallization occur in 6016 aluminum alloy during hot compressing, and strong rolling textures such as （110） fiber texture, Brass, S, and Goss form. With the deformation passes increasing, （110） fiber texture, Brass and S are enhanced. In the heat preservation stage after deformation, recrystallization continues until heat preser- vation for 60 s, and a duplex microstructure of deformation and recrystallization grains is built. At the beginning of heat preservation, recrystallization grains with the Goss texture and random orientation are formed in original grains with S or Brass texture, which makes the volume fraction of S and Brass texture decrease. Then, the complex grain growth process makes the volume fraction of Brass, S, and Goss texture increase, while that of random orien- tation decrease.
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The authors are grateful to the National Natural Science Foundation of China(Grant Nos.52034004 and 52271111)the National Key R&D Program of China(2022YFB3705300)for grant and financial support.
文摘Interfacial evolution and bonding mechanism of reduced activation ferritic/martensitic(RAFM)steel were systematically investigated through a series of hot compression tests conducted at various strains(0.15-0.8),strain rates(0.001-1 s^(-1)),and temperatures(950-1050℃).Interfacial microstructural analysis revealed that plastic deformation of surface asperities effectively removes interfacial voids,and the evolution of dynamic recrystallization(DRX)aids in achieving a joint characterized by homogeneously refined microstructure and adequate interfacial grain boundary(IGB)migration.Electron backscattered diffraction analysis demonstrated that the continuous dynamic recrystallization,characterized by progressive subgrain rotation,is the prevailing DRX nucleation mechanism in RAFM steel during hot compression bonding.During DRX evolution,emerging DRX grains in the interfacial region expand into adjacent areas,transforming T-type triple junction grain boundaries into equal form,and resulting in a serrated and intricate interface.Elevated temperatures and strains,coupled with reduced strain rates,augment DRX grain nucleation and IGB migration,thus enhancing RAFM joint quality with regard to the interface bonding ratio and the interface migration ratio.
基金General Project,Scientific Research Project Plan for Traditional Chinese Medicine in Hebei Province(Project No.:T2025117)。
文摘Objective:To explore the application of external application of Traditional Chinese Medicine(TCM)hot compress package combined with Kinesio Taping in postoperative nursing of total knee arthroplasty.Methods:90 patients with severe knee osteoarthritis who underwent total knee arthroplasty in our department from January to December 2022 were randomly divided into two groups using a random number table method:one group was named the conventional group(n=45),which received the standard orthopedic nursing process throughout,including basic pain management,incision care,and functional exercise guidance;the other group was defined as the experimental group(n=45),which,in addition to the conventional nursing framework,incorporated the local transdermal drug delivery technique of TCM hot compress package and the biomechanical correction scheme of Kinesio Taping for collaborative intervention.Finally,the differences in postoperative resting/active pain scores(VAS)of the affected limb and satisfaction with nursing services between the two groups were compared using quantitative assessment tools.Results:The satisfaction with nursing care in the conventional group was significantly lower than that in the experimental group(P<0.05);the VAS score after nursing in the conventional group was significantly higher than that in the experimental group(P<0.05).Conclusion:The application of external application of TCM hot compress package combined with Kinesio Taping in postoperative nursing of total knee arthroplasty has a definite effect,reducing pain and improving patient satisfaction with nursing services.
基金supported by the Graduate Education Innovation Program of Shanxi Province,China(No.2024KY575)the National Natural Science Foundation of China(No.52075501)。
文摘A Mg−13Gd−4Y−2Zn−0.5Zr(wt.%)alloy was selected as the experimental material.After preheating,initial microstructures with different long-period stacking ordered(LPSO)phase andβ'phase distributions were obtained,and hot compression experiments were conducted.The effects of secondary phases on microstructure and dynamic recrystallization(DRX)behavior were investigated.The results revealed that the average grain size decreased from 70.93 to 31.53μm,and the DRX volume fraction increased from 20.3%to 40.1%after the pre-annealing treatment.The average grain size of Sample S0(pre-aging)decreased to 39.29μm,and the DRX volume fraction increased by 79.8%,whereas the average grain size of Samples S1−S7(pre-annealing+aging)slightly increased,and the DRX volume fraction slightly decreased.With increasing pre-annealing time,the width of the lamellar LPSO phase increased,which generated less dynamic precipitation during deformation and weakened the pinning effect.The DRX mechanism transformed from continuous dynamic recrystallization(CDRX,pre-homogenization sample)to particle-stimulated nucleation(PSN)+discontinuous dynamic recrystallization(DDRX,pre-annealing sample).After the pre-aging treatment,the reticular structure effectively pinned the dislocations and delayed the nucleation and growth of DRX grains.The DRX mechanism changed from the original CDRX+PSN(pre-aging sample)to DDRX(pre-annealing+aging sample).
文摘Plastometric experiments,supplemented with numerical simulations using the finite element method(FEM),can be advantageously used to characterize the deformation behavior of metallic materials.The accuracy of such simulations predicting deformation behaviors of materials is,however,primarily affected by the applied rheology law.The presented study focuses on the characterization of the deformation behavior of AISI 1045 type carbon steel,widely used e.g.,in automotive and power engineering,under extreme conditions(i.e.,high temperatures,strain rates).The study consists of two main parts:experimentally analyzing the flow stress development of the steel under different thermomechanical conditions via uniaxial hot compression tests and establishing the rheology law via numerical simulations implementing the experimentally acquired flow stress curves.The numerical simulations then not only serve to establish the rheology law but also to verify the reliability of the selected experimental process.The results of the numerical simulations showed that the established rheology law characterizes the behavior of the investigated steel with sufficient accuracy also at high temperatures and/or strain rates,and can,therefore,be used for practical purposes.Last but not least,supplementary microstructure analyses performed for the samples subjected to the highest deformation temperature provided a deeper insight into the effects of the applied(extreme)thermomechanical conditions on the behavior of the investigated steel.
基金financially supported by the National Key Research and Development Program of China(No.2022YFE0109600)the National Natural Science Foundation of China(No.52150710544)。
文摘An additional hot compression process was applied to a dilute Mg−Mn−Zn alloy post-extrusion.The alloy was extruded at 150℃ with an extrusion ratio of 15:1 and subsequently hot-compressed at 180℃ with a true strain of 0.9 along the extrusion direction.The microstructure,mechanical properties and thermal conductivity of as-extruded and as-hot compressed Mg−Mn−Zn alloys were investigated using optical microscopy,scanning electron microscopy,electron backscattering diffraction,and transmission electron microscopy.The aim was to concurrently enhance both strength and thermal conductivity by fostering uniform and refined microstructures while mitigating basal texture intensity.Substantial improvements were observed in yield strength(YS),ultimate tensile strength(UTS),and elongation(EL),with increase of 77%,53% and 10%,respectively.Additionally,thermal conductivity demonstrated a notable enhancement,rising from 111 to 125 W/(m·K).The underlying mechanism driving these improvements through the supplementary hot compression step was thoroughly elucidated.This study presents a promising pathway for the advancement of Mg alloys characterized by superior thermal and mechanical properties.
基金supported by the National Natural Science Foundation of China(Grant Nos.52233017,51774265,52301032,and 52173305)the National Key Research and Development Program(Grant No.2018YFA0702900)+2 种基金the National Science and Technology Major Project of China(Grant No.2019ZX06004010)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDC04000000)the LingChuang Research Project of China National Nuclear Corporation,CNNC Science Fund for Talented Young Scholars,the Program of CAS Interdisciplinary Innovation Team,and the Youth Innovation Promotion Association,CAS.
文摘An innovative method of hot compression bonding is proposed in this work for the joining of 9Cr oxide dispersion strengthened(ODS)alloy and 9Cr reduced-activation ferritic/martensitic(RAFM)alloy.The microstructural evolution of the bonding interface was investigated by scanning electron microscopy(SEM),electron back-scattered diffraction(EBSD),and transmission electron microscopy(TEM).The results verify that the pinning effect of nano-oxides particles(NPs)in 9Cr ODS alloy significantly enhances its dynamic recrystallization(DRX)temperature and deformation resistance.Continuous DRX(CDRX)first occurred on the 9Cr RAFM alloy side,and the areas near the bonding interface were composed of recrystallized grains.With increasing strain,CDRX also showed up on the 9Cr ODS alloy side.Inevitable slight oxidation occurred at the bonding interface during the hot compression bonding(HCB)process,and the interfacial oxides transformed from initial coarse CrO to TiO and finally to Y-Ti-O nanoparticles with sizes comparable to pre-existing NPs dispersed in the 9Cr ODS alloy matrix.It is believed that interfacial oxide transformation and grain structure consistency contributed to the excellent interface healing of the two dissimilar alloy pieces.The effectiveness of the bonding was tested by tensile tests and fractography analysis,revealing that ideal metallurgical bonding could be achieved under a controlled strain level of 10%at 800℃ followed by soaking at 1000℃ for 4 h.
基金Project(51301065)supported by the National Natural Science Foundation of ChinaProject(15B063)supported by the Youth Research Foundation of Education Bureau of Hunan Province,China
文摘Hot deformation behavior of extrusion preform of the spray-formed Al-9.0Mg-0.5Mn-0.1Ti alloy was studied using hot compression tests over deformation temperature range of 300-450 ℃ and strain rate range of 0.01-10 s-1. On the basis of experiments and dynamic material model, 2D processing maps and 3D power dissipation maps were developed for identification of exact instability regions and optimization of hot processing parameters. The experimental results indicated that the efficiency factor of energy dissipate （η） lowered to the minimum value when the deformation conditions located at the strain of 0.4, temperature of 300 ° C and strain rate of 1 s-1. The softening mechanism was dynamic recovery, the grain shape was mainly flat, and the portion of high angle grain boundary （〉15°） was 34%. While increasing the deformation temperature to 400 ° C and decreasing the strain rate to 0.1 s-1, a maximum value of η was obtained. It can be found that the main softening mechanism was dynamic recrystallization, the structures were completely recrystallized, and the portion of high angle grain boundary accounted for 86.5%. According to 2D processing maps and 3D power dissipation maps, the optimum processing conditions for the extrusion preform of the spray-formed Al？9.0Mg？0.5Mn？0.1Ti alloy were in the deformation temperature range of 340-450 ° C and the strain rate range of 0.01-0.1 s-1 with the power dissipation efficiency range of 38%？43%.
文摘Background: Although a number of studies have reported that the hot and humid compress from traditional Chinese medicine (TCM) is effective in treating lumbar disc herniation (LDH) with qi stagnation and blood stasis, clinical evidence is limited. Objective: The purpose of this study is to provide high-quality evidence to support the effectiveness of the traditional Chinese hot and humid compress in the treatment of LDH with qi stagnation and blood stasis. Methods: From October 2021 to November 2023, 86 patients with LDH of qi stagnation and blood stasis type were recruited in our hospital and divided into a control (n = 43) and an observation group (n = 43) according to the random number table method. The control group was given routine clinical treatment, and the observation group was treated with the hot and humid compress therapy for two weeks. The visual analogue scale (VAS) score, Japanese Orthopaedic Association (JOA) score, TCM syndrome score, serum interleukin-6 (IL-6), serum interleukin-1β (IL-1β), and tumor necrosis factor-α (TNF-α) were observed and compared between the two groups before and after treatment, and the clinical efficacy of the two groups was evaluated. Results: After treatment, the VAS score, TCM symptom score, and serum IL-6, IL-1β, and TNF-α levels decreased in both groups (P P P P P Conclusions: The hot and humid compress of traditional Chinese medicine can effectively relieve pain, restore lumbar function, improve TCM syndromes, reduce the level of inflammatory factors, and have a curative effect in treating LDH.
基金Project(51101052) supported by the National Natural Science Foundation of China
文摘The high-temperature deformation behavior of Cu-Ni-Si-P alloy was investigated by using the hot compression test in the temperature range of 600-800 ℃ and strain rate of 0.01-5 s-1. The hot deformation activation energy, Q, was calculated and the hot compression constitutive equation was established. The processing maps of the alloy were constructed based on the experiment data and the forging process parameters were then optimized based on the generated maps for forging process determination. The flow behavior and the microstructural mechanism of the alloy were studied. The flow stress of the Cu-Ni-Si-P alloy increases with increasing strain rate and decreasing deformation temperature, and the dynamic recrystallization temperature of alloy is around 700 ℃. The hot deformation activation energy for dynamic recrystallization is determined as 485.6 kJ/mol. The processing maps for the alloy obtained at strains of 0.3 and 0.5 were used to predict the instability regimes occurring at the strain rate more than 1 s-1 and low temperature （〈650 ℃）. The optimum range for the alloy hot deformation processing in the safe domain obtained from the processing map is 750-800 ℃ at the strain rate of 0.01-0.1 s i The characteristic microstructures predicted from the processing map agree well with the results of microstructural observations.
基金Project(51271203)supported by the National Natural Science Foundation of ChinaProject(CX2012B037)supported by the Hunan Provincial Innovation Foundation for Postgraduate,China+1 种基金Project(2013zzts017)supported by the Graduate Degree Thesis Innovation Foundation of Central South University,ChinaProject(2012bjjxj015)supported by the Excellent Doctor Degree Thesis Support Foundation of Central South University,China
文摘Hot compression test of a novel nickel-free white alloy Cu?12Mn?15Zn?1.5Al?0.3Ti?0.14B?0.1Ce (mass fraction, %) was conducted on a Gleeble?1500 machine in the temperature range of 600?800 °C and the strain rate range of 0.01?10 s?1. The constitutive equation and hot processing map of the alloy were built up according to its hot deformation behavior and hot working characteristics. The deformation activation energy of the alloy is 203.005 kJ/mol. An instability region appears in the hot deformation temperature of 600?700 °C and the strain rate range of 0.32?10 s?1 when the true strain of the alloy is up to 0.7. Under the optimal hot deformation condition of 800 °C and 10 s?1 the prepared specimen has good surface quality and interior structure. The designed nickel-free alloy has very similar white chromaticity with the traditional white copper alloy (Cu?15Ni?24Zn?1.5Pb), and the color difference between them is less than 1.5, which can hardly be distinguished by human eyes.
基金Project(11JJ2025)supported by Natural Science Foundation of Hunan Province,ChinaProject(y2010-01-004)supported by the Nonferrous Metals Science Foundation of HNG-CSU,China
文摘The hot deformation behavior of a novel imitation-gold copper alloy was investigated with Gleeble-1500 thermo-mechanical simulator in the temperature range of 650-770 °C and strain rate range of 0.001-1.0 s-1. The hot deformation constitutive equation was established and the thermal activation energy was obtained to be 249.60 kJ/mol. The processing map at a strain of 1.2 was developed. And there are two optimal regions in processing map, namely 650-680 °C, 0.001-0.01 s-1 and 740-770 °C, 0.01-0.1 s-1. Optical microscopy was employed to investigate the microstructure evolution of the alloy in the process of deformation. Recrystallized grains and twin crystals were found in microstructures of the hot deformed alloy.
基金Project (51005112) supported by the National Natural Science Foundation of ChinaProject (2010ZF56019) supported by the Aviation Science Foundation of China+1 种基金Project (GJJ11156) supported by the Education Commission of Jiangxi Province, ChinaProject(GF200901008) supported by the Open Fund of National Defense Key Disciplines Laboratory of Light Alloy Processing Science and Technology, China
文摘The high temperature deformation behaviors of α＋β type titanium alloy TC11 （Ti-6.5Al-3.5Mo-1.5Zr-0.3Si） with coarse lamellar starting microstructure were investigated based on the hot compression tests in the temperature range of 950-1100 ℃ and the strain rate range of 0.001-10 s-1. The processing maps at different strains were then constructed based on the dynamic materials model, and the hot compression process parameters and deformation mechanism were optimized and analyzed, respectively. The results show that the processing maps exhibit two domains with a high efficiency of power dissipation and a flow instability domain with a less efficiency of power dissipation. The types of domains were characterized by convergence and divergence of the efficiency of power dissipation, respectively. The convergent domain in a＋fl phase field is at the temperature of 950-990 ℃ and the strain rate of 0.001-0.01 s^-1, which correspond to a better hot compression process window of α＋β phase field. The peak of efficiency of power dissipation in α＋β phase field is at 950 ℃ and 0.001 s 1, which correspond to the best hot compression process parameters of α＋β phase field. The convergent domain in β phase field is at the temperature of 1020-1080 ℃ and the strain rate of 0.001-0.1 s^-l, which correspond to a better hot compression process window of β phase field. The peak of efficiency of power dissipation in ℃ phase field occurs at 1050 ℃ over the strain rates from 0.001 s^-1 to 0.01 s^-1, which correspond to the best hot compression process parameters of ,8 phase field. The divergence domain occurs at the strain rates above 0.5 s^-1 and in all the tested temperature range, which correspond to flow instability that is manifested as flow localization and indicated by the flow softening phenomenon in stress-- strain curves. The deformation mechanisms of the optimized hot compression process windows in a＋β and β phase fields are identified to be spheroidizing and dynamic recrystallizing controlled by self-diffusion mechanism, respectively. The microstructure observation of the deformed specimens in different domains matches very well with the optimized results.
基金Project(2011CB612200)supported by the National Basic Research Program of China
文摘The compressive deformation behavior of as-quenched 7005 aluminum alloy was investigated at the temperature ranging from 250 °C to 450 °C and strain rate ranging from 0.0005 s-1 to 0.5 s^-1 on Gleeble-1500 thermal-simulation machine. Experimental results show that the flow stress of as-quenched 7005 alloy is affected by both deformation temperature and strain rate, which can be represented by a Zener-Hollomon parameter in an exponent-type equation. By comparing the calculated flow stress and the measured flow stress, the results show that the calculated flow stress agrees well with the experimental result. Based on a dynamic material model, the processing maps were constructed for the strains of 0.1, 0.3 and 0.5. The maps and microstructural examination revealed that the optimum hot working domain is 270-340 °C, 0.05-0.5 s^-1 with the reasonable dynamic recrystallization. The instability domain exhibits adiabatic shear bands and flow localization, which should be avoided during hot working in order to obtain satisfactory properties.
基金Project(20130161110007) supported by the Doctoral Program of the Ministry of Education,ChinaProject(CX2013B128) supported by Hunan Provincial Innovation Foundation for Postgraduate,ChinaProject(201306130021) supported by the Chinese Scholarship Council
文摘The AA7150 aluminum alloy was compressed to various strains at strain rate of 10 s（-1） and temperatures of 300 °C and 450 °C, respectively. Flow stress behavior, substructure evolution, morphology and spatial distribution of precipitates were studied based on differential scanning calorimetry analysis and transmission electron microscope observation. The results showed that dynamic flow softening occurs during hot deformation. The main softening mechanism could be concluded as dynamic recovery at 300 °C and continuous dynamic recrystallization at 450 °C. The clear heterogeneous spatial distributions of precipitates are found during deformation and enhanced with increased strain. Higher contents of Cu in T phases are found at 450 °C than at 300 °C, which present a transformation process from T phases to S phases as well. The associated evidence of dynamic precipitation on dislocations and particle-stimulated nucleation, as well as the detailed microstructural inherited relationship and morphological texture（particles preferred orientation） were characterized.
基金Project(2011BAE22B01-1)supported by the National Key Technologies R&D Program of ChinaProject(2011DFA50903)supported by the International S&T Cooperation Program of China
文摘The hot compression behavior of a wrought Mg-6Zn-1Al-0.3Mn magnesium alloy was investigated using Gleeble test at 200-400 °C with strain rates ranging from 0.01 to 7 s-1. The true stress-strain curves show that the hot deformation behavior significantly depends on the deformation temperature and strain rate. The calculated hot deformation activation energy Q is 166 kJ/mol with a stress exponent n=5.99, and the constitutive equation is deduced to be ε＆ =3.16×1013[sinh（0.010σ）]5.99exp [-1.66×105/（RT）]· Deformation microstructure shows that the incompletely dynamically recrystallized grains can be found at grain boundaries and twins with the strain rates ranging from 0.01 to 1 s^-1 at 250 °C, and completely dynamic recrystallization occurs when the temperature is 350 °C or above during hot compression, the size of recrystallized grains decreases with the increment of the strain rate at the same temperature. The relatively suitable deformation condition is considered temperature 330-400 °C and strain rate of 0.01-0.03 s-1, and temperature of 350 °C and strain rate of 1 s-1.
文摘Hot compression tests were conducted on a homogenized Mg-7Gd-4Y-1Nd-0.5Zr alloy at 450 ℃ and a strain rate of 2 s-1. Dynamic recrystallization （DRX） mechanisms were investigated by optical microscope （OM）, scanning electron microscope （SEM） and transmission electron microscope （TEM） systematically. The crystallographic orientation information is obtained through electron back-scattering diffraction （EBSD）. The result shows that the flow stress firstly reaches a peak rapidly followed by declining to a valley, and then increases gradually again when the alloy is compressed to a strain of-1.88. DRX related to {10]2} tensile twins is extensively observed at small strains, resulting in an evident grain refinement. DRX grains first nucleate along the edges of twin boundaries with about 30~ （0001） off the twin parents. While at large strains, conventional continuous DRX （CDRX） is frequently identified by the formation of small DRX grains along the original grain boundaries and the continuously increasing misorientation from the centre of large original grains to the grain boundaries. Evidence of particle-stimulated nucleation （PSN） is also observed in the present alloy.
文摘TA2 pure titanium was chosen to research the interaction among deformation, recrystallization and phase transformation during hot compression. The samples were hot compressed by thermal simulation method with different processing parameters. Variant selection induced by stress during cooling after compression was found. The prismatical texture component which featured that the [0001] direction perpendicular to the compressing direction produced preferentially under the compressing stress. As a result, the transformedα phase possesses strong prismatical texture which is different with the basal texture of compressed αphase. The minimum elastic strain energy is demonstrated to be the main reason that causes the variant selection. Dynamic recrystallization behavior and microstructure evolution during hot compression were also studied.
基金Project (2010DFA52280) supported by International Science and Technology CooperationProject (20100470260) supported by China Postdoctoral Science Foundation
文摘The hot deformation behavior of Ti-3.0Al-3.7Cr-2.0Fe-0.1B (TACFB) titanium alloy was investigated using a Gleeble-1500D thermal simulator in the temperature range of 800-950 °C, at constant strain rate from 0.01 s-1 to 10 s-1 and with height reduction of 70%. Flow stress and microstructure evolution during hot compression of TACFB alloy were investigated. The processing map of TACFB alloy was obtained. The results indicate that the hot deformation behavior of TACFB alloy is sensitive to the deformation temperature and strain rate. The peak flow stress decreases with increasing the test temperature and decreasing the strain rate. The constitutive relationship of TACFB alloy was obtained on the base of Arrhenius equations. When the strain rates are higher than 1.0 s-1, the dynamic recrystallization occurs, and the higher the strain rates are, the more the recrystallization is.
