旋转反挤压与常规反挤压Mg-Gd-Y-Zn-Zr合金杯形件显微组织对比研究  

Differential Study on the Effect of Rotary Back-extrusion and Conventional Back-extrusion on the Microstructure of Mg-Gd-Y-Zn-Zr Alloy Cuprates

作　　者：徐健[1] 乔为栋 闫钊鸣 薛勇[1] Xu Jian;Qiao Weidong;Yan Zhaoming;Xue Yong(School of Materials Science and Engineering,North University of China,Taiyuan 030051,China)

机构地区：[1]中北大学材料科学与工程学院,山西太原030051

出　　处：《稀有金属材料与工程》2024年第9期2653-2660,共8页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(52075501,52205428);山西省基础研究计划(20210302124206)。

摘　　要：使用传统反挤压(conventional backward extrusion,CBE)和旋转反挤压(rotational backward extrusion,RBE)2种工艺制备了不同的Mg-9Gd-4Y-2Zn-0.5Zr(质量分数,%)合金杯形件。使用OM、SEM、EBSD等测试方法对不同杯形件的对应区域进行表征。结果表明:RBE的晶粒细化能力远远大于CBE,RBE心部的晶粒细化效果最好,RBE-Ⅲ区域的动态再结晶(dynamic recrystallization,DRX)含量可达98.1%,平均晶粒尺寸为2.5μm。RBE的织构弱化能力也优于CBE,心部的织构强度可弱化为1.258。在RBE得到杯形件当中,其长周期堆积有序相(LPSO)相的破碎程度也大于CBE,第二相(β相)分布得也更加均匀,析出的β相可以通过粒子刺激形核(particles simulated nucleation,PSN)机制促进DRX,并通过钉扎效应抑制晶粒长大。在CBE和RBE杯形件成形过程中,其动态再结晶机制相同,为连续动态再结晶(continuous dynamic recrystallization,CDRX)和不连续动态再结晶(discontinuous dynamic recrystallization,DDRX)2种。Different cuprates of Mg-9Gd-4Y-2Zn-0.5Zr(wt%)alloys were prepared by conventional backward extrusion(CBE)and rotational backward extrusion(RBE)processes.The corresponding regions of the different cuprates were characterized by OM,SEM,EBSD and other testing methods.The results show that the grain refining ability of RBE is much stronger than that of CBE,and the grain refining effect in the heart of RBE is the best,and the content of dynamic recrystallization(DRX)in the RBE-III region can be up to 98.1%,with an average grain size of 2.5μm.The texture weakening ability of RBE is also better than that of CBE,and the texture strength of the core can be weakened to 1.258.In the RBE cups,the degree of crushing of the LPSO phase is also larger than that of CBE,and the distribution of the second phase(βphase)is more uniform,and the precipitatedβphase can promote DRX through the mechanism of particles simulated nucleation(PSN)and restrain the growth of the grains through the pinning effect.In CBE and RBE cup molding processes,the dynamic recrystallization mechanism is the same,which is continuous dynamic recrystallization(CDRX)and discontinuous dynamic recrystallization(DDRX).

关 键 词：旋转反挤压 杯形件 Mg-Gd-Y-Zn-Zr合金 动态再结晶 LPSO相 

分 类 号：TG376[金属学及工艺—金属压力加工] TG146.22[一般工业技术—材料科学与工程]