摘要
研究了大体积AZ91D镁合金在SIMA法制备半固态浆料过程中组织的演变规律,并对半固态组织球状化演变的影响因素进行了分析.结果表明:合金在550℃等温处理时,α相在升温阶段就开始由树枝晶向团块状转变,随等温时间的延长再由团块状逐渐演变为多边形状,最后演变为球状晶;若等温时间过长,晶粒会发生合并长大;随着等温温度的升高,组织的球状化速度加快,相同等温时间下晶粒的平均尺寸减小;随着保温时间延长,晶粒圆整度明显改善;增加预形变量将促进半固态等温时枝晶形貌的转变,形变量越大的试样转变为球状晶的速度越快,所需时间越短.
The microstructure evolution of AZ91D magnesium alloy semisolid slurry in the SIMA process was investigated, and the influencing factors on spherical microstructure evolution were analyzed. The results show that during the heating stage at 550℃, the morphology of primary α phase changes firstly from dendrites to nubbly crystal, with increasing soaking time it changes gradually from nubbly to polygon and spherical crystal. As soaking time over, combination of grains occurs. With the rising soaking temperature, the grain spherodization accelerates and the average dimension of grains diminishes at the same soaking time. With the remaining soaking time the grains get rounded, and the increasing deformation rate facilitates the morphology transition of dendrite at the same soaking temperature. The higher the deformation rate is, the faster the dendrite crystal transforms, and the shorter the time spent for the microstructure evolution.
出处
《西安交通大学学报》
EI
CAS
CSCD
北大核心
2006年第5期591-595,共5页
Journal of Xi'an Jiaotong University
基金
陕西省教育厅产业化培育项目(02JC33)
西安市工业科技攻关项目(GG200247)
关键词
镁合金
压缩形变
半固态等温
组织演变
magnesium alloy
compressive deformation
semisolid soaking
microstructure evolu tion
