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

作　　者：Qi Zeng Yingbo Zhang Kangning Li Ye Zhuang Jiaheng Li Yong JYuan Dongdi Yin 

机构地区：[1]School of Materials Science and Engineering,Southwest Jiaotong University,No.111,North 1st Section of Sec,Chengdu,Sichuan 610031,China [2]Weichai Power Co.,Fushou East Street,High-Tech Development Zone,Weifang 261061,China

出　　处：《Journal of Magnesium and Alloys》2023年第2期533-542,共10页镁合金学报（英文）

基　　金：supported by the International Science and Technology Innovation Cooperation Program of Sichuan Province,China (Grant No. 2019YFH0095);the National Natural Science Foundation of China (Grant No. 51201142);the Major Scientific and Technological special Project of Yunnan Provincial Science and Technology Department(202002AB080001-4)。

摘　　要：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 temperature.The high ductility from the combined effects of the grain refinement, dispersion of nanoscale I-phase particles, and the unusual texture.The 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 

分 类 号：TG146[一般工业技术—材料科学与工程]