挤压道次对真空电弧重熔Mg-22Nd-15Al-8Zn-1.5Y合金组织及性能的影响  

Influence of extrusion pass on microstructure and properties of Mg-22Nd-15Al-8Zn-1.5Y alloy by vacuum arc remelting

作　　者：张丹丹[1] 杨泽华[2] 陈冲[1] 张恩平 孙菊 Zhang Dandan;Yang Zehua;Chen Chong;Zhang Enping;Sun Ju(Department o£Urban Rail Transportation,Zhengzhou Polytechnic,Zhengzhou 450121,China;Department of Architectural Engineering,Zhengzhou Polytechnic,Zhengzhou 450121,China;Zhengzhou Metro Group Co.,Ltd.,Zhengzhou 450121,China;School of Materials Science and Engineering,Henan Polytechnic University,Jiaozuo 454000,China)

机构地区：[1]郑州职业技术学院城市轨道交通系,河南郑州450121 [2]郑州职业技术学院建筑工程系,河南郑州450121 [3]郑州地铁集团有限公司,河南郑州450121 [4]河南理工大学材料科学与工程学院,河南焦作454000

出　　处：《锻压技术》2022年第4期176-180,共5页Forging & Stamping Technology

基　　金：河南省科技厅科技攻关计划项目(172102210567)。

摘　　要：选择真空电弧重熔工艺制备Mg-22Nd-15Al-8Zn-1.5Y合金,镁合金作为基材,通过挤压工艺在镁合金基体中加入Mg-Nd中间合金,并分析挤压道次对其组织结构与力学特性的影响。研究结果表明:当挤压道次达到5时,在镁合金组织内已观察不到大晶粒,产生了许多尺寸很小的第二相颗粒;经过多次挤压变形处理后,在挤压方向出现了明显的塑性流动,形成了具有明显纤维形态的组织;合金组织的晶界区域形成了许多尺寸较小的Mg-Nd中间合金,表现为团簇状态,对晶界可以发挥良好的钉扎效果,使位错运动受到明显抑制,从而获得更高的力学强度;对试样进行5道次挤压后,拉伸强度增大至322 MPa,伸长率变为7.3%,获得了更优的力学性能;挤压过程中,一些中间合金颗粒发生了破碎,并在高密度位错部位发生形核,能够抑制再结晶晶粒生长。The Mg-22 Nd-15 Al-8 Zn-1.5 Y alloy was prepared by vacuum arc remelting(VAR) process. Then, taking magnesium alloy as the based material, Mg-Nd intermediate alloy was added to the magnesium alloy matrix by extrusion process, and the influences of extrusion pass on the microstructure and mechanical properties of Mg-22 Nd-15 Al-8 Zn-1.5 Y alloy were analyzed. The results show that when the extrusion pass reaches five, no large grains are observed in the magnesium alloy microstructure, and many small second phase particles are generated. After many times of extrusion deformation treatment, obvious plastic flow appears in the extrusion direction, and the structure with obvious fiber shape is formed. Many small Mg-Nd intermediate alloys are formed in the grain boundary region of the alloy, which are in the form of clusters and can exert a good pinning effect on the grain boundary and significantly inhibit the dislocation movement to obtain higher mechanical strength. After five passes of extrusion, the tensile strength of specimen increases to 322 MPa, the elongation becomes 7.3%, and the better mechanical properties are obtained. During the extrusion process, some intermediate alloy particles are broken and nucleated at the position of high density dislocations to inhibit the growth of recrystallized grains.

关 键 词：真空电弧重熔 挤压道次 镁合金 显微组织 力学性能 

分 类 号：TG146[一般工业技术—材料科学与工程]