半固态冷却方式对二次挤压Mg-3.88Zn-1.56Gd合金组织和力学性能的影响  

Effect of Semi-solid Cooling Methods on Microstructure and Mechanical Properties of Secondary Extruded Mg-3.88Zn-1.56Gd Alloy

作　　者：曾崎 张英波[1] 庄野 胡云峰 张普 李茉嘉 Zeng Qi;Zhang Yingbo;Zhuang Ye;Hu Yunfeng;Zhang Pu;Li Mojia(School of Materials Science and Engineering,Southwest Jiaotong University,Chengdu 610031,China)

机构地区：[1]西南交通大学材料科学与工程学院,四川成都610031

出　　处：《稀有金属材料与工程》2022年第7期2625-2630,共6页Rare Metal Materials and Engineering

基　　金：四川省国际科技创新合作项目(2019YFH0095);云南省科技厅重大科技专项(202002AB080001-4)。

摘　　要：本工作研究了半固态(淬火或者空冷)以及热挤压对Mg-3.88Zn-1.56Gd(%,质量分数,下同)合金显微组织和力学性能的影响。结果表明半固态后淬火,第二相在合金中呈现纳米级共晶层片组织,而半固态后空冷,第二相在合金中呈三叉岛、块状和微米层片状。经过二次挤压,由于不完全再结晶,半固态+挤压后的合金均呈现典型的双峰组织。与未半固态直接二次挤压合金相比,半固态+挤压的合金均具有较高的强度。合金性能增强主要原因是由于双峰组织的形成,细小晶粒提供了晶界强化,未再结晶的粗晶粒则是通过抑制基面滑移,从而产生增强效果。其次要原因是准晶相的细化及其在基体中的弥散分布。The effects of semi-solid(quenching or air cooling) and hot extrusion on the microstructure and me chanical properties of Mg-3.88Zn-1.56Gd alloy were studied. The results show that after semi-solid quenching, the second phase presents nano eutectic lamellar structure in the alloy, while after semi-solid air cooling, the second phase presents trigeminal island, block and micron lamellar structure in the alloy. After secondary extrusion, the semi-solid+extruded alloy presents typical bimodal structure due to incomplete recrystallization.Compared with the non semi-solid alloy, the semi-solid+extruded alloy exhibits higher strength. The main reason for the performance enhancement of the alloy is due to the formation of bimodal structure. The fine grains provide the grain boundary strengtheni ng, while the coarse grains without recrystallization produce the strengthening effect by inhibiting the base plane slip. The second important reason is the refinement of quasicrystal phase and its dispersion in the matrix.

关 键 词：镁合金 双峰组织 半固态等温处理 再结晶 

分 类 号：TG146.22[一般工业技术—材料科学与工程]