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Designing new low alloyed Mg-RE alloys with high strength and ductility via high-speed extrusion

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International Journal of Minerals,Metallurgy and Materials 2023年第1期30卷 82-91页

作者： Jinshu Xie Zhi Zhang Shujuan Liu Jinghuai Zhang Jun Wang Yuying He Liwei Lu Yunlei Jiao Ruizhi Wu Key Laboratory of Superlight Material and Surface Technology Ministry of EducationCollege of Materials Science and Chemical EngineeringHarbin Engineering UniversityHarbin 150001China School of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150001China Ningbo Branch Ordnance Science Institute of ChinaNingbo 315103China School of Materials Science and Engineering Hunan University of Science and TechnologyXiangtan 411201China

Two new low-alloyed Mg-2RE-0.8Mn-0.6Ca-0.5Zn(wt%,RE=Sm or Y)alloys are developed,which can be produced on an in-dustrial scale via relatively high-speed *** two alloys are not only comparable to commercial AZ31 alloy in extrudability,but also have superior mechanical properties,especially in terms of yield strength(YS).The excellent extrudability is related to less coarse second-phase particles and high initial melting point of the two as-cast *** high strength-ductility mainly comes from the formation of fine grains,nano-spaced submicron/nano precipitates,and weak ***,it is worth noting that the YS of the two alloys can maintain above 160 MPa at elevated temperature of 250°C,significantly higher than that of AZ31 alloy(YS:45 MPa).The Zn/Ca solute segregation at grain boundaries,the improved heat resistance of matrix due to addition of RE,and the high melting points of strengthening particles(Mn,MgZn_(2),and Mg-Zn-RE/Mg-Zn-RE-Ca)are mainly responsible for the excellent high-temperature strength.

关键词： magnesium alloys high-speed extrusion high strength high ductility solute segregation

high-ductility fine-grained Mg-1.92Zn-0.34Y alloy fabricated by semisolid and then hot extrusion

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Journal of Magnesium and Alloys 2023年第2期11卷 533-542页

作者： Qi Zeng Yingbo Zhang Kangning Li Ye Zhuang Jiaheng Li Yong JYuan Dongdi Yin School of Materials Science and Engineering Southwest Jiaotong UniversityNo.111North 1st Section of SecChengduSichuan 610031China Weichai Power Co. Fushou East StreetHigh-Tech Development ZoneWeifang 261061China

The combination of semisolid and hot extrusion processing was applied to refine the icosahedral quasicrystalline phase(I-phase) in an extruded Mg-1.92Zn-0.34Y(wt.%) alloy for the first time. The semisolid isothermal heat treatment transformed the micron-sized I-phase particles into nano lamellar eutectic(α-Mg + I-phase) with a lamellar spacing of ?86 nm. After subsequent hot extrusion at 250 ℃, the nano lamellar eutectic phases were broken into uniformly dispersed nanoscale I-phase particles. What’s more, the matrix microstructure was significantly refined with an equiaxed average grain size of 2.59 ± 0.81 μm, and an unusual texture component(most of the grains’ c-axis is parallel to the extrusion direction) was observed. The processed alloy exhibited a high tensile elongation to failure(EL) of 44 ± 2.6%with an ultimate tensile strength(UTS) of 258 ± 2.0 MPa and a tensile yield strength(TYS) of 176 ± 1.6 MPa at room *** high ductility from the combined effects of the grain refinement, dispersion of nanoscale I-phase particles, and the unusual *** uniform dispersion of nanoscale I-phase particles could promote grain refinement by particle stimulated nucleation mechanism, and thus bring the unusual texture(where the c-axis is aligned parallel to the extrusion direction during dynamic recrystallization, which contributed to ductility).

关键词： high ductility Unusual texture Nanoscale I-phase particle Microstructure

Effect of fiber type on the bending and uniaxial tensile properties of high-strength high-ductility cementitious composites

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Journal of Southeast University(English Edition) 2018年第4期34卷 495-499页

作者： Guo Liping Chen Bo Wu Yue Lei Dongyi School of Materials Science and Engineering Southeast UniversityNanjing 211189China Jiangsu Key Laboratory of Construction Materials Southeast UniversityNanjing 211189China State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Nanjing Hydraulic Research InstituteNanjing 210029China

To investigate the effect of fiber types on bending and tensile properties of high-strength,high-ductility cementitious composites( HS-HDCCs), ultra-high-molecular-weight polyethylene( PE) fibers,polyvinyl alcohol( PVA) fibers,and copper-plated micro steel fibers were selected as the reinforcement materials. The bending and tensile properties of HS-HDCCs with different fibers with a volume fraction of 2% were studied. The results indicate that PE,PVA,micro steel,and PVA-PE hybrid fibers impart varying degrees of toughening and improve the tensile strength. During the tensile and bending processes,HS-HDCCs with micro steel fibers exhibit a strain-softening phenomenon. HS-HDCCs with PVA fibers or with PVA-PE hybrid fibers can achieve multiple cracking behaviors and strain hardening phenomenon to a certain extent and show slight high-ductility characteristics. HS-HDCCs with PE fibers exhibit multiple cracking behavior and strain hardening phenomenon and show significant high-ductility characteristics. The test results can provide a basis for selecting fibers suitable for HS-HDCCs reinforcement.

关键词： fiber high ductility toughness uniaxial tensile

Recent developments of the high strength and high ductility nanostructured materials

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Baosteel Technical Research 2010年第S1期4卷 93-页

作者： Jian LU,Aiying CHEN,Hongning KOU,Ying LI,Leyu WANG and Chunsheng WEN Department of Mechanical Engineering,The Hong Kong Polytechnic University,Hung Hom Kowloon,Hong Kong,China

This talk will summarize the recent work related to a kind of new nanomaterials produced by the SMAT (surface mechanical attrition treatment).The concept of surface nanocrystallization of materials will be *** terms of the grain refinement mechanism induced by plastic deformation,a novel surface mechanical attrition(SMA) technique was developed for synthesizing a nanostructured surface layer on metallic materials in order to upgrade the overall properties and *** grain refinement mechanism of the surface layer during the SMA treatment will be analyzed in terms of the nanostructure observations in several typical *** high yield stress(5 times of the base material) on the surface layer of the material obtained by the SMAT has been *** effect of surface nanostructures on the mechanical behavior and on the failure mechanism of metallic material shows the possibility to develop a new strength gradient composite using co-rolling and *** role of residual stress induced during the treatment will be investigated and *** developed materials are also porosity free materials which can be used as reference material for the local mechanical behavior investigation technique such as the nanoindentation.A general concept for obtaining high strength and high ductility nanostructured materials will be *** exceptional high strength and high ductility steels have *** simulation of the mechanisms for improving ductility of high strength nanostructured materials will be *** potential applications for the land transportation vehicles(car,bus,train) and wind energy have been *** examples of concept design for the integration of the advanced nanostructured steels will be presented.

关键词： nanostructured materials high strength high ductility surface mechanical attrition treatment(SMAT)

Toward the development of Mg alloys with simultaneously improved strength and ductility by refining grain size via the deformation process

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International Journal of Minerals,Metallurgy and Materials 2021年第1期28卷 30-45页

作者： Zhi Zhang Jing-huai Zhang Jun Wang Ze-hua Li Jin-shu Xie Shu-juan Liu Kai Guan Rui-zhi Wu Key Laboratory of Superlight Material and Surface Technology Ministry of EducationCollege of Material Science and Chemical EngineeringHarbin Engineering UniversityHarbin 150001China Ningbo Branch Ordnance Science Institute of ChinaNingbo 315103China Department of Materials Physics and Chemistry Harbin Institute of TechnologyHarbin 150001China

Magnesium(Mg) alloys, as the lightest metal engineering materials, have broad application ***, the strength and ductility of traditional Mg alloys are still relativity low and difficult to improve *** grain size via the deformation process based on the grain boundary strengthening and the transition of deformation mechanisms is one of the feasible strategies to prepare Mg alloys with high strength and high *** this review, the effects of grain size on the strength and ductility of Mg alloys are summarized, and fine-grained Mg alloys with high strength and high ductility developed by various severe plastic deformation technologies and improved traditional deformation technologies are *** some achievements have been made, the effects of grain size on various Mg alloys are rarely discussed systematically and some key mechanisms are unclear or lack direct microscopic *** review can be used as a reference for further development of high-performance fine-grained Mg alloys.

关键词： magnesium alloys grain refinement high strength high ductility deformation process

Microstructure and performance evaluations on Q&P hot stamping parts of several UHSS sheet metals

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Science China(Technological Sciences) 2017年第11期60卷 1692-1701页

作者： HAN XianHong ZHONG YaoYao TAN ShuLin DING YaNan CHEN Jun Department of Plasticity Technology Shanghai Jiao Tong UniversityShanghai 200030China SAIC Motor Technical Center Shanghai 201804China

Hot stamping(press hardening) is widely used to fabricate safety components such as door beams and B pillars with increased strength via quenching. However, parts that are hot-stamped from ultra-high-strength steel(UHSS) have very limited elongation,i.e., low ductility. In the present study, a novel variant of hot stamping technology called quenching-and-partitioning(Q&P) hot stamping was developed. This approach was tested on several UHSS sheet metals, and it was confirmed that this method can be used to overcome the drawbacks associated with conventional hot stamping. The applicability of Q&P hot stamping to each of these steels was also assessed. The part properties and performances of three widely used ultra-high-strength sheet metals, B1500 HS,27 SiMn, and TRIP780, were evaluated through tensile testing and microstructural observations. The results demonstrated that the ductility of Q&P hot-stamped sheet metals was notably higher than that of the conventionally hot-stamped parts because Q&P hot stamping gives rise to a dual-phase structure of both martensite and austenite. Further, material tests demonstrated that the Q&P treatment had positive effects on all three selected materials, of which TRIP780 had the best ductility and the highest value of the product of strength and plasticity. Scanning electron microscopy images indicated that the silicon in the steels could limit the formation of cementite and would, therefore, improve the mechanical properties of Q&P hot-stamped products.

关键词： ultra-high-strength steel hot stamping quenching and partitioning process high ductility

Microstructure and mechanical properties of friction-stir-welded high-Mg-alloyed Al-Mg alloy plates at different rotating rates

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Rare Metals 2021年第8期40卷 2167-2178页

作者： Ying-Li Li Wei-Jun Xia Hong-Ge Yan Ji-Hua Chen Tian Ding You-Ping Sun Xin-Yu Li School of Materials Science and Engineering Hunan UniversityChangsha410082China Hunan Provincial Key Laboratory of Spray Deposition Technology and Application Hunan UniversityChangsha410082China School of Mechanical and Transportation Engineering Guangxi University of Science and TechnologyLiuzhou545006China

Hot-rolled high-Mg-alloyed Al-Mg alloy(Al-9.2 Mg-0.8 Mn-0.2 Zr-0.15 Ti,labeled as 5 A12)plates were successfully friction stir welded at rotating rates ranging from 750 to 1500 r·min^(-1) at a constant welding speed of50 mm·min^(-1).The joints were characterized by optical microscopy(OM),electron backscatter diffraction(EBSD),transmission electron microscopy(TEM),scanning electron microscopy(SEM),electron-dispersive spectroscopy(EDS),and tensile *** the joints are volume defectfree and exhibit fine,equiaxed dynamic recrystallization(DRX)grains with high-angle grain boundaries(HAGBs)fractions of 88.6%-93.3%in the nugget zones(NZs).The DRX grain size and the second-phase particle size in the NZs have a parabolic relation with the rotating ***,among the joints tested,the joint prepared at1000 r·min^(-1),which has the highest ultimate tensile strength((478±3)MPa)and the largest elongation to rupture(22.5%±1.4%)—approximately 87.5%and145.2%those of the base metal,respectively,exhibits the smallest grain size of 2.93μm,as well as the smallest particle size in the *** excellent mechanical properties can be ascribed to the combined effects of the fine DRX grains with high fraction of HAGBs and the fine second-phase particles with a uniform distribution.

关键词： Al-Mg alloy Friction stir welding Dynamic recrystallization high ductility

A Study of the Microstructure and Properties of Dual-Phase Steels Processed Using A Continuous Galvanizing Line Simulation: The Benefits of Optimized Hot and Cold Rolling and the Addition of Vanadium

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A Study of the Microstructure and Properties of Dual-Phase S...