As a new attempt to recycle minute metal scraps, the possibility of manufacturing design materials by semisolid extrusion processing was shown.A design material with an intended shape, such as a character or petal sha...As a new attempt to recycle minute metal scraps, the possibility of manufacturing design materials by semisolid extrusion processing was shown.A design material with an intended shape, such as a character or petal shape, was manufactured using minute metal scraps.Similarly, a design material with an intended color pattern for each metal, such as red copper in a white aluminum matrix, resembling grainlike wood, was manufactured by mixing two or more types of minute metal scrap.In addition, secondary design materials, which have engraved patterns on the surface of the target metal made by an electric discharge machine using the above primary design material as an electrode, were manufactured.展开更多
We investigated image processing algorithms of the original infrared glass flaw image. Using the Laplacian edge enhancement following LSD （Line Segment Detector） algorithm, we can get a good flaw image very consiste...We investigated image processing algorithms of the original infrared glass flaw image. Using the Laplacian edge enhancement following LSD （Line Segment Detector） algorithm, we can get a good flaw image very consistent with the original one. This study is very helpful to further enhance the infrared glass flaw inspection technique.展开更多
Effects of cold rolling followed by annealing on microstructural evolution and superelastic properties of the Ti50Ni48Co2 shape memory alloy were investigated. Results showed that during cold rolling, the alloy micros...Effects of cold rolling followed by annealing on microstructural evolution and superelastic properties of the Ti50Ni48Co2 shape memory alloy were investigated. Results showed that during cold rolling, the alloy microstructure evolved through six basic stages including stress-induced martensite transformation and plastic deformation of martensite, deformation twinning, accumulation of dislocations along twin and variant boundaries in martensite, nanocrystallization, amorphization and reverse transformation of martensite to austenite. After annealing at 400 ℃ for 1 h, the amorphous phase formed in the cold-rolled specimens was completely crystallized and an entirely nanocrystalline structure was achieved. The value of stress level of the upper plateau in this nanocrystalline alloy was measured as high as 730 MPa which was significantly higher than that of the coarse-grained Ni50Ti50 and Ti50Ni48Co2 alloys. Moreover, the nanocrystalline Ti50Ni48Co2 alloy had a high damping capacity and considerable efficiency for energy storage.展开更多
Mg alloys,as a new generation of biodegradable bone implant materials,are facing two tremendous challenges of enhancing strength and reducing degradation rate in physiological environment to meet clinical needs.In thi...Mg alloys,as a new generation of biodegradable bone implant materials,are facing two tremendous challenges of enhancing strength and reducing degradation rate in physiological environment to meet clinical needs.In this study,tricalcium phosphate(β-TCP)particles were dispersed in Mg–2 Zn–0.46 Y–0.5 Nd alloy by friction stir processing(FSP)to produce Mg-based functional gradient materials(Mg/β-TCP FGM).On the surface of Mg/β-TCP FGM,the hydroxyapatite(HA)coating was prepared by electrodeposition.The effects of FSP and electrochemical parameter on the microstructure,microhardness,bonding strength and corrosion performance of the Mg/β-TCP FGM were investigated.After four passes of FSP,a uniform and fine-grained structure was formed in Mg/β-TCP and the microhardness increased from 47.9 to 76.3 HV.Compared to the samples withoutβ-TCP,the bonding strength of the Mg/β-TCP FGM increased from 23.1±0.462 to 26.3±0.526 MPa and the addition of degradableβ-TCP contributed to the in situ growth of HA coating.The thickness of HA coating could be dominated by controlling the parameters of electrodeposition.According to the results of immersion tests and electrochemical tests in simulated body fluid,it indicated that the degradation rate of the Mg/β-TCP FGM could be adjusted.展开更多
The DGW-I is a new material processing facility developed in China,which was firstly carried into orbit in November 1999 by the SZ-1 spacecraft and then in January 2001 carried by SZ-2 into space again,and successfull...The DGW-I is a new material processing facility developed in China,which was firstly carried into orbit in November 1999 by the SZ-1 spacecraft and then in January 2001 carried by SZ-2 into space again,and successfully processed 6 samples of materials,including 3 samples of alloys,2 of semiconductors and 1 sample of oxide crystal.展开更多
Microstructural modifications and appropriate element doping are necessary to simultaneously enhance the electrical conductivities and reduce the lattice thermal conductivities of thermoelectric materials.Herein,we pr...Microstructural modifications and appropriate element doping are necessary to simultaneously enhance the electrical conductivities and reduce the lattice thermal conductivities of thermoelectric materials.Herein,we propose a strategy of multielement doping combined with a burial sintering process to promote thermoelectric properties.Three-element doped Sr0.9La0.05Dy0.05Ti1-xNbxO3(x=0,0.05,0.10,0.15,and 0.20)powders were synthesized by high-energy ball milling,and corresponding bulk samples were prepared by carbon burial sintering.In the bulk samples,we obtained the desired microstructures composed of shell-vesicular architectures with dense dislocations and second phase particles.These materials had ultrahigh electrical conductivities(~5300 S cm^-1 at 300 K),low lattice thermal conductivities(~1.6 Wm^-1 K^-1 from 700 to 1100 K when x=0.2)and low total thermal conductivities(minimum value of 2.95 Wm^-1 K^-1 when x=0.05 at 1100 K).The maximum zT values were 0.28 when x=0.05 and 0.27 when x=0.2 at 1100 K.This strategy provides a possible direction for improving the thermoelectric properties of SrTiO3 based materials.展开更多
Friction stir spot welding technique was used to join dissimilar combinations of aluminium alloy(Al5052)with copperalloy(C27200)and friction stir spot welding windows such as tool rotational speed–dwell time and tool...Friction stir spot welding technique was used to join dissimilar combinations of aluminium alloy(Al5052)with copperalloy(C27200)and friction stir spot welding windows such as tool rotational speed–dwell time and tool rotational speed?plungedepth diagrams for effective joining of these materials were developed.Using a central composite design model,empirical relationswere developed to predict the changes in tensile shear failure load values and interface hardness of the joints with three processparameters such as tool rotational speed,plunge depth and dwell time.The adequacy of the developed model was verified usingANOVA analysis at95%confidence level.Response surface methodology was used to optimize the developed model to maximizetensile strength and minimize interface hardness.A high tensile shear failure load value of3850N and low interface hardness valueof HV81was observed for joints made under optimum conditions,and validation experiments confirmed the high predictability ofthe developed model with error less than2%.The operating windows developed shall act as reference maps for future designengineers in choosing appropriate friction stir spot welding process parameter values to obtain good joints.展开更多
The research achievements of solidification theories and technologies in the last decades are reviewed with the stresses on some new development in the recent years. Some new interesting areas emerged in the last year...The research achievements of solidification theories and technologies in the last decades are reviewed with the stresses on some new development in the recent years. Some new interesting areas emerged in the last years are also pointed out.展开更多
The First Pacific Rim International Confer-ence on Advanced Materials and Processing(PRICM-1)organized by The Chinese Society ofMetals(CSM),and co-sponsored by the Japan In-stitute of Metals(JIM),the Korean Institute ...The First Pacific Rim International Confer-ence on Advanced Materials and Processing(PRICM-1)organized by The Chinese Society ofMetals(CSM),and co-sponsored by the Japan In-stitute of Metals(JIM),the Korean Institute ofMetals(KIM)and The Mineral,Metals & Materi-als Society of the United States(TMS),was held inShangri-La Hotel,Hangzhou,China on June24-27,1992.It was the first large international conference展开更多
Author researches a lot of the mathematical models and the related conventional material constants in the traditional and the modem mechanics; to adopt two types of variables a and D, for the fatigue-damage-fracture b...Author researches a lot of the mathematical models and the related conventional material constants in the traditional and the modem mechanics; to adopt two types of variables a and D, for the fatigue-damage-fracture behaviors to elastic-plastic steels contained flaws, to put forward several calculation models, which are the driving force and the life prediction expressions at each stage and in whole process; for the key parameters .A1 and ,A2 in two stages, there are functional relation with other conventional material constants σF,m1 and M2,λ2, they are defined as the new calculable comprehensive material constants, and indicate their physical and geometrical meanings. In addition, for conversion methods between two types of variables, relevant calculating example is provided. Thereby, make a linking between the fracture mechanics and the damage mechanics, communicating their relationships. This works for saving man powers and funds on fatigue-damage-fracture testing that will be having practical significance.展开更多
Microwave processing has been taken into consideration for various purposes,not only for cooking,drying and enhancement of solution reaction kinetics but also various high temperature processes.In the presentation,sel...Microwave processing has been taken into consideration for various purposes,not only for cooking,drying and enhancement of solution reaction kinetics but also various high temperature processes.In the presentation,selected research projects conducted in our group will be reported.The first topic is the microwave processing for recycling valuable metals from by-products originated in the iron and steel industries.We studied microwave application to handling of the pickling sludge,which occurs in stainless steel rolling process.Microwave use for dehydration and carbo-thermic reduction processes was attempted.Next,because Pb elution from the wasted funnel glass used for the cathod-ray tube is one of the serious environmental problems,microwave application to leaching process of Pb from a Pb-conatining glass was performed.The kinetic study of the acid dissolution was performed.Last topic is fabrication of filter material for burning particulate matter(PM)from diesel engine(Diesel Particulate Filter:DPF).Microwave rapid heating characteristics are applied to the cold start(ignition)condition of engine for prevention of PM emission.展开更多
The research activities in EPM for several metallic materials are classified in the application of different magnetic field.The following research is exhibited in this article,(1)Effect of magnetic field on solidifica...The research activities in EPM for several metallic materials are classified in the application of different magnetic field.The following research is exhibited in this article,(1)Effect of magnetic field on solidification process of monotectic alloys;(2)Effect of high magnetic field on fabrication of high-strength and high-conductivity copper alloys;(3)Numerical simulation of magnetic field and fluid flow in continuous casting mold with vertical electromagnetic brake;(4)Research on solidification structure of superalloy with EMS;(5)Effects of static magnetic field on the behavior of meniscus in a mold under argon gas injection.展开更多
A new concept named computational comminution is proposed in thispaper, which is different from the traditional studies on materialsprocessing procedure such as the study based on theoretic models, thestudy based on e...A new concept named computational comminution is proposed in thispaper, which is different from the traditional studies on materialsprocessing procedure such as the study based on theoretic models, thestudy based on experiment models, which is based on informationmodels. Some key technologies applied to mate- rials processingprocedure such as artificial neural networks, fuzzy sets, geneticalgorithms and visualization techn- ology are also presented, and afusing methodology of these new technologies is studied. Applicationin the cement grinding process of Horomill shows that results in thispaper are efficient.展开更多
Development and application of new ceramic die materials is one of the important topics in the field of die research. The composition, processing technology, mechanical property and engineering performance of the cera...Development and application of new ceramic die materials is one of the important topics in the field of die research. The composition, processing technology, mechanical property and engineering performance of the ceramic materials such as cermet, ZTA, TZP, TZP/Al2O3, TZP/TiC/Al2O3, PSZ and Sialon, etc., with rare earth yttrium, lanthanum and cerium, and so on working as additives, were investigated and analyzed in the present study. Problems existed in the research and application of rare earth ceramic die materials were discussed. Rare earth additives can effectively improve the mechanical property and engineering performance of ceramic die materials. Thus, it will have further perspectives of wider application. More attention should be paid in the future to the toughening and strengthening of the ceramic die materials, the adding forms and kinds of rare earth elements and acting mechanisms of rare earth additives in ceramic die materials.展开更多
A dynamic contact problem for elastic-viscoplastic materials with thermal effects is investigated. The contact is bilateral, and the friction is modeled with Tresca＇s friction law with heat exchange. A variational fo...A dynamic contact problem for elastic-viscoplastic materials with thermal effects is investigated. The contact is bilateral, and the friction is modeled with Tresca＇s friction law with heat exchange. A variational formulation of the model is derived, and the existence of a unique weak solution is proved. The proofs are based on the classical result of nonlinear first order evolution inequalities, the equations with monotone operators, and the fixed point arguments. Finally, the continuous dependence of the solution on the friction yield limit is studied.展开更多
Refill friction stir spot welding(RFSSW)provides a novel method to join similar and/or dissimilar metallic materials without a key-hole in the center of the joint.Having the key-hole free characterization,the similar/...Refill friction stir spot welding(RFSSW)provides a novel method to join similar and/or dissimilar metallic materials without a key-hole in the center of the joint.Having the key-hole free characterization,the similar/dissimilar RFSSW joint exhibits remarkable and endurable characteristics,including high shear strength,long fatigue life,and strong corrosion resistance.In the meanwhile,as the key-hole free joint has different microstructures compared with conventional friction stir spot welding,thus the RFSSW joint shall possess different shear and fatigue fracture mechanisms,which needs further investigation.To explore the underlying failure mechanism,the similar/dissimilar metallic material joining parameters and pre-treatment,mechanical properties,as well as fracture mechanisms under this novel technology will be discussed.In details,the welding tool design,welding parameters setting,and the influence of processing on the lap shear and fatigue properties,as well as the corrosion resistance will be mainly discussed.Moreover,the roadmap of RFFSW is also discussed.展开更多
The exponential growth of literature is constraining researchers’access to comprehensive information in related fields.While natural language processing(NLP)may offer an effective solution to literature classificatio...The exponential growth of literature is constraining researchers’access to comprehensive information in related fields.While natural language processing(NLP)may offer an effective solution to literature classification,it remains hindered by the lack of labelled dataset.In this article,we introduce a novel method for generating literature classification models through semi-supervised learning,which can generate labelled dataset iteratively with limited human input.We apply this method to train NLP models for classifying literatures related to several research directions,i.e.,battery,superconductor,topological material,and artificial intelligence(AI)in materials science.The trained NLP‘battery’model applied on a larger dataset different from the training and testing dataset can achieve F1 score of 0.738,which indicates the accuracy and reliability of this scheme.Furthermore,our approach demonstrates that even with insufficient data,the not-well-trained model in the first few cycles can identify the relationships among different research fields and facilitate the discovery and understanding of interdisciplinary directions.展开更多
Pulsed external field, including electric, magnetic, ultrasonic and laser, as aninstantaneous high energy input method with high efficiency and low energyconsumption, have long been known to can modify the microstruct...Pulsed external field, including electric, magnetic, ultrasonic and laser, as aninstantaneous high energy input method with high efficiency and low energyconsumption, have long been known to can modify the microstructure and propertiesof materials. This includes electroplasticity, magnetoplasticity, phase transformations,recrystallization, grain refinement, texture control, inclusion removal.展开更多
The Joint Conference Organizing Committee of The Chinese Society of Metals(CSM),The Japan Insti-tute of Metals(JIM),The Korean Institute of Metals(KIM)and The Minerals,Metals & Materials Society(TMS)announces The ...The Joint Conference Organizing Committee of The Chinese Society of Metals(CSM),The Japan Insti-tute of Metals(JIM),The Korean Institute of Metals(KIM)and The Minerals,Metals & Materials Society(TMS)announces The First Pacific Rim International Conference on Advanced Materials and Processing(PRICM-1)which will be held in Hangzhou,China,in the last week of June,1992 lasting about four days.It is agreed that the PRICM-1 will be organized by The Chinese Society of Metals.展开更多
文摘As a new attempt to recycle minute metal scraps, the possibility of manufacturing design materials by semisolid extrusion processing was shown.A design material with an intended shape, such as a character or petal shape, was manufactured using minute metal scraps.Similarly, a design material with an intended color pattern for each metal, such as red copper in a white aluminum matrix, resembling grainlike wood, was manufactured by mixing two or more types of minute metal scrap.In addition, secondary design materials, which have engraved patterns on the surface of the target metal made by an electric discharge machine using the above primary design material as an electrode, were manufactured.
基金Funded by the Program for New Century Excellent Talents in University (11-0687)the National Natural Science Foundation of China (51172169)the Fundamental Research Funds for the Central Universities (Wuhan University of Technology)
文摘We investigated image processing algorithms of the original infrared glass flaw image. Using the Laplacian edge enhancement following LSD （Line Segment Detector） algorithm, we can get a good flaw image very consistent with the original one. This study is very helpful to further enhance the infrared glass flaw inspection technique.
文摘Effects of cold rolling followed by annealing on microstructural evolution and superelastic properties of the Ti50Ni48Co2 shape memory alloy were investigated. Results showed that during cold rolling, the alloy microstructure evolved through six basic stages including stress-induced martensite transformation and plastic deformation of martensite, deformation twinning, accumulation of dislocations along twin and variant boundaries in martensite, nanocrystallization, amorphization and reverse transformation of martensite to austenite. After annealing at 400 ℃ for 1 h, the amorphous phase formed in the cold-rolled specimens was completely crystallized and an entirely nanocrystalline structure was achieved. The value of stress level of the upper plateau in this nanocrystalline alloy was measured as high as 730 MPa which was significantly higher than that of the coarse-grained Ni50Ti50 and Ti50Ni48Co2 alloys. Moreover, the nanocrystalline Ti50Ni48Co2 alloy had a high damping capacity and considerable efficiency for energy storage.
基金financial support of the National Natural Science Foundation of China(No.U1804251)the National Key Research and Development Program of China(Nos.2018YFC1106703 and 2017YFB0702504).
文摘Mg alloys,as a new generation of biodegradable bone implant materials,are facing two tremendous challenges of enhancing strength and reducing degradation rate in physiological environment to meet clinical needs.In this study,tricalcium phosphate(β-TCP)particles were dispersed in Mg–2 Zn–0.46 Y–0.5 Nd alloy by friction stir processing(FSP)to produce Mg-based functional gradient materials(Mg/β-TCP FGM).On the surface of Mg/β-TCP FGM,the hydroxyapatite(HA)coating was prepared by electrodeposition.The effects of FSP and electrochemical parameter on the microstructure,microhardness,bonding strength and corrosion performance of the Mg/β-TCP FGM were investigated.After four passes of FSP,a uniform and fine-grained structure was formed in Mg/β-TCP and the microhardness increased from 47.9 to 76.3 HV.Compared to the samples withoutβ-TCP,the bonding strength of the Mg/β-TCP FGM increased from 23.1±0.462 to 26.3±0.526 MPa and the addition of degradableβ-TCP contributed to the in situ growth of HA coating.The thickness of HA coating could be dominated by controlling the parameters of electrodeposition.According to the results of immersion tests and electrochemical tests in simulated body fluid,it indicated that the degradation rate of the Mg/β-TCP FGM could be adjusted.
文摘The DGW-I is a new material processing facility developed in China,which was firstly carried into orbit in November 1999 by the SZ-1 spacecraft and then in January 2001 carried by SZ-2 into space again,and successfully processed 6 samples of materials,including 3 samples of alloys,2 of semiconductors and 1 sample of oxide crystal.
基金supported financially by the National Key Research and Development Program of China(No.2017YFA0403803)the National Natural Science Foundation of China(Nos.51971052,51774065,51927801 and 51525401)+1 种基金LiaoNing Revitalization Talents Program(No.XLYC1808005)the Dalian Support Plan for Innovation of High-level Talents(2017RQ026)。
文摘Microstructural modifications and appropriate element doping are necessary to simultaneously enhance the electrical conductivities and reduce the lattice thermal conductivities of thermoelectric materials.Herein,we propose a strategy of multielement doping combined with a burial sintering process to promote thermoelectric properties.Three-element doped Sr0.9La0.05Dy0.05Ti1-xNbxO3(x=0,0.05,0.10,0.15,and 0.20)powders were synthesized by high-energy ball milling,and corresponding bulk samples were prepared by carbon burial sintering.In the bulk samples,we obtained the desired microstructures composed of shell-vesicular architectures with dense dislocations and second phase particles.These materials had ultrahigh electrical conductivities(~5300 S cm^-1 at 300 K),low lattice thermal conductivities(~1.6 Wm^-1 K^-1 from 700 to 1100 K when x=0.2)and low total thermal conductivities(minimum value of 2.95 Wm^-1 K^-1 when x=0.05 at 1100 K).The maximum zT values were 0.28 when x=0.05 and 0.27 when x=0.2 at 1100 K.This strategy provides a possible direction for improving the thermoelectric properties of SrTiO3 based materials.
文摘Friction stir spot welding technique was used to join dissimilar combinations of aluminium alloy(Al5052)with copperalloy(C27200)and friction stir spot welding windows such as tool rotational speed–dwell time and tool rotational speed?plungedepth diagrams for effective joining of these materials were developed.Using a central composite design model,empirical relationswere developed to predict the changes in tensile shear failure load values and interface hardness of the joints with three processparameters such as tool rotational speed,plunge depth and dwell time.The adequacy of the developed model was verified usingANOVA analysis at95%confidence level.Response surface methodology was used to optimize the developed model to maximizetensile strength and minimize interface hardness.A high tensile shear failure load value of3850N and low interface hardness valueof HV81was observed for joints made under optimum conditions,and validation experiments confirmed the high predictability ofthe developed model with error less than2%.The operating windows developed shall act as reference maps for future designengineers in choosing appropriate friction stir spot welding process parameter values to obtain good joints.
文摘The research achievements of solidification theories and technologies in the last decades are reviewed with the stresses on some new development in the recent years. Some new interesting areas emerged in the last years are also pointed out.
文摘The First Pacific Rim International Confer-ence on Advanced Materials and Processing(PRICM-1)organized by The Chinese Society ofMetals(CSM),and co-sponsored by the Japan In-stitute of Metals(JIM),the Korean Institute ofMetals(KIM)and The Mineral,Metals & Materi-als Society of the United States(TMS),was held inShangri-La Hotel,Hangzhou,China on June24-27,1992.It was the first large international conference
文摘Author researches a lot of the mathematical models and the related conventional material constants in the traditional and the modem mechanics; to adopt two types of variables a and D, for the fatigue-damage-fracture behaviors to elastic-plastic steels contained flaws, to put forward several calculation models, which are the driving force and the life prediction expressions at each stage and in whole process; for the key parameters .A1 and ,A2 in two stages, there are functional relation with other conventional material constants σF,m1 and M2,λ2, they are defined as the new calculable comprehensive material constants, and indicate their physical and geometrical meanings. In addition, for conversion methods between two types of variables, relevant calculating example is provided. Thereby, make a linking between the fracture mechanics and the damage mechanics, communicating their relationships. This works for saving man powers and funds on fatigue-damage-fracture testing that will be having practical significance.
文摘Microwave processing has been taken into consideration for various purposes,not only for cooking,drying and enhancement of solution reaction kinetics but also various high temperature processes.In the presentation,selected research projects conducted in our group will be reported.The first topic is the microwave processing for recycling valuable metals from by-products originated in the iron and steel industries.We studied microwave application to handling of the pickling sludge,which occurs in stainless steel rolling process.Microwave use for dehydration and carbo-thermic reduction processes was attempted.Next,because Pb elution from the wasted funnel glass used for the cathod-ray tube is one of the serious environmental problems,microwave application to leaching process of Pb from a Pb-conatining glass was performed.The kinetic study of the acid dissolution was performed.Last topic is fabrication of filter material for burning particulate matter(PM)from diesel engine(Diesel Particulate Filter:DPF).Microwave rapid heating characteristics are applied to the cold start(ignition)condition of engine for prevention of PM emission.
基金Item Sponsored by the National Natural Science Foundation of China[No.50834009]Wuhan National High Magnetic Field Center[No.WHMFCKF201107]+2 种基金Key Grant Project of China Ministry of Education (No.311014) National High Technology Research and Development Program 863[No.2007AA03Z519]the 111 Project of China (No.B07015)
文摘The research activities in EPM for several metallic materials are classified in the application of different magnetic field.The following research is exhibited in this article,(1)Effect of magnetic field on solidification process of monotectic alloys;(2)Effect of high magnetic field on fabrication of high-strength and high-conductivity copper alloys;(3)Numerical simulation of magnetic field and fluid flow in continuous casting mold with vertical electromagnetic brake;(4)Research on solidification structure of superalloy with EMS;(5)Effects of static magnetic field on the behavior of meniscus in a mold under argon gas injection.
文摘A new concept named computational comminution is proposed in thispaper, which is different from the traditional studies on materialsprocessing procedure such as the study based on theoretic models, thestudy based on experiment models, which is based on informationmodels. Some key technologies applied to mate- rials processingprocedure such as artificial neural networks, fuzzy sets, geneticalgorithms and visualization techn- ology are also presented, and afusing methodology of these new technologies is studied. Applicationin the cement grinding process of Horomill shows that results in thispaper are efficient.
基金Project supported by National Natural Science Foundation of China (50405047)Natural Science foundation of Shandong Province (Y2005F04)Jinan Young Star Plan of Science and Technology (08108)
文摘Development and application of new ceramic die materials is one of the important topics in the field of die research. The composition, processing technology, mechanical property and engineering performance of the ceramic materials such as cermet, ZTA, TZP, TZP/Al2O3, TZP/TiC/Al2O3, PSZ and Sialon, etc., with rare earth yttrium, lanthanum and cerium, and so on working as additives, were investigated and analyzed in the present study. Problems existed in the research and application of rare earth ceramic die materials were discussed. Rare earth additives can effectively improve the mechanical property and engineering performance of ceramic die materials. Thus, it will have further perspectives of wider application. More attention should be paid in the future to the toughening and strengthening of the ceramic die materials, the adding forms and kinds of rare earth elements and acting mechanisms of rare earth additives in ceramic die materials.
文摘A dynamic contact problem for elastic-viscoplastic materials with thermal effects is investigated. The contact is bilateral, and the friction is modeled with Tresca＇s friction law with heat exchange. A variational formulation of the model is derived, and the existence of a unique weak solution is proved. The proofs are based on the classical result of nonlinear first order evolution inequalities, the equations with monotone operators, and the fixed point arguments. Finally, the continuous dependence of the solution on the friction yield limit is studied.
基金This work was supported by International Science and Technology Cooperation Project of Guangdong Province(Grant No.2022A0505050054)Innovation and Technology Fund(ITF)(Grant No.ITP/021/19AP)National Natural Science Foundation of China(Grant No.51905112).
文摘Refill friction stir spot welding(RFSSW)provides a novel method to join similar and/or dissimilar metallic materials without a key-hole in the center of the joint.Having the key-hole free characterization,the similar/dissimilar RFSSW joint exhibits remarkable and endurable characteristics,including high shear strength,long fatigue life,and strong corrosion resistance.In the meanwhile,as the key-hole free joint has different microstructures compared with conventional friction stir spot welding,thus the RFSSW joint shall possess different shear and fatigue fracture mechanisms,which needs further investigation.To explore the underlying failure mechanism,the similar/dissimilar metallic material joining parameters and pre-treatment,mechanical properties,as well as fracture mechanisms under this novel technology will be discussed.In details,the welding tool design,welding parameters setting,and the influence of processing on the lap shear and fatigue properties,as well as the corrosion resistance will be mainly discussed.Moreover,the roadmap of RFFSW is also discussed.
基金funded by the Informatization Plan of Chinese Academy of Sciences(Grant No.CASWX2021SF-0102)the National Key R&D Program of China(Grant Nos.2022YFA1603903,2022YFA1403800,and 2021YFA0718700)+1 种基金the National Natural Science Foundation of China(Grant Nos.11925408,11921004,and 12188101)the Chinese Academy of Sciences(Grant No.XDB33000000)。
文摘The exponential growth of literature is constraining researchers’access to comprehensive information in related fields.While natural language processing(NLP)may offer an effective solution to literature classification,it remains hindered by the lack of labelled dataset.In this article,we introduce a novel method for generating literature classification models through semi-supervised learning,which can generate labelled dataset iteratively with limited human input.We apply this method to train NLP models for classifying literatures related to several research directions,i.e.,battery,superconductor,topological material,and artificial intelligence(AI)in materials science.The trained NLP‘battery’model applied on a larger dataset different from the training and testing dataset can achieve F1 score of 0.738,which indicates the accuracy and reliability of this scheme.Furthermore,our approach demonstrates that even with insufficient data,the not-well-trained model in the first few cycles can identify the relationships among different research fields and facilitate the discovery and understanding of interdisciplinary directions.
文摘Pulsed external field, including electric, magnetic, ultrasonic and laser, as aninstantaneous high energy input method with high efficiency and low energyconsumption, have long been known to can modify the microstructure and propertiesof materials. This includes electroplasticity, magnetoplasticity, phase transformations,recrystallization, grain refinement, texture control, inclusion removal.
文摘The Joint Conference Organizing Committee of The Chinese Society of Metals(CSM),The Japan Insti-tute of Metals(JIM),The Korean Institute of Metals(KIM)and The Minerals,Metals & Materials Society(TMS)announces The First Pacific Rim International Conference on Advanced Materials and Processing(PRICM-1)which will be held in Hangzhou,China,in the last week of June,1992 lasting about four days.It is agreed that the PRICM-1 will be organized by The Chinese Society of Metals.
