Effects of Extrusion Speed on the Microstructure and Mechanical Properties of Mg-9Gd-3Y-1.5Zn-0.8Zr alloy  

作　　者：Xuan Liu Zhiqiang Zhang Wenyi Hu Qichi Le Lei Bao Jianzhong Cui 

机构地区：[1]Key Lab of Electromagnetic Processing of Materials, Ministry of Education, Northeastern University, Shenyang 110819, China

出　　处：《Journal of Materials Science & Technology》2016年第4期313-319,共7页材料科学技术（英文版）

基　　金：financially supported by the National Basic Research Program of China (No. 2013CB632203);the Liaoning Provincial Natural Science Foundation of China (No. 2014028027)

摘　　要：The effects of the extrusion speed on the microstructures, mechanical properties and aging hardening behaviors of Mg-9Gd-3Y-1.5Zn-0.8Zr alloy have been investigated. The microstructure evolution during hot extrusion has also been discussed. The microstructures of the extruded alloys mainly consist of the equiaxed dynamically recrystallized grains and fiber-like long period stacking ordered （LPSO） phase. The increasing extrusion speed results in grain coarsening and the mechanical properties deterioration. Mean- while, it could also retard the aging hardening response. The extrudability of the investigated alloy is limited. Cracks nucleate and grow up rapidly when the extrusion speed is over 0.3 m/min. It should be closely related to the large amount of LPSO phase and the unique microstructure evolution. The rapidly precipitating fine lamella during extrusion could pin the dislocations and grain boundaries effectively. It could strengthen the alloy but also limit the extrudability of the investigated alloy.The effects of the extrusion speed on the microstructures, mechanical properties and aging hardening behaviors of Mg-9Gd-3Y-1.5Zn-0.8Zr alloy have been investigated. The microstructure evolution during hot extrusion has also been discussed. The microstructures of the extruded alloys mainly consist of the equiaxed dynamically recrystallized grains and fiber-like long period stacking ordered （LPSO） phase. The increasing extrusion speed results in grain coarsening and the mechanical properties deterioration. Mean- while, it could also retard the aging hardening response. The extrudability of the investigated alloy is limited. Cracks nucleate and grow up rapidly when the extrusion speed is over 0.3 m/min. It should be closely related to the large amount of LPSO phase and the unique microstructure evolution. The rapidly precipitating fine lamella during extrusion could pin the dislocations and grain boundaries effectively. It could strengthen the alloy but also limit the extrudability of the investigated alloy.

关 键 词：Mg--Gd--Y--Zn--Zr alloyHot extrusionExtrusion speedMicrostructuresAging hardeningMechanical properties 

分 类 号：TG379[金属学及工艺—金属压力加工] TG146.21[一般工业技术—材料科学与工程]