AZ91D镁合金屑制备半固态坯料的均匀性及组织演变  

Microstructure Homogeneity and Evolution of Semi-solid Billet Prepared with AZ91D Alloy Chips

作　　者：丁佳伟[1] 许红雨[1] 王鑫[1] 兰文仲 吉泽升[1] 杉山澄雄[1,2] 

机构地区：[1]哈尔滨理工大学材料科学与工程学院 [2]东京大学生产技术研究所

出　　处：《特种铸造及有色合金》2017年第1期52-56,共5页Special Casting & Nonferrous Alloys

基　　金：国家自然科学基金资助项目(51574100);哈尔滨理工大学大学生创新创业训练项目(27)

摘　　要：以AZ91D镁合金屑料为原料,采用热压制工艺和半固态等温处理制备半固态坯料,通过显微组织观察和定量金相分析研究了半固态组织均匀性及组织演变。结果表明,在热压制工艺参数下,压坯密度为1.76g/cm3,相对密度可达98%,晶粒得到显著的细化,组织均匀分布。经半固态等温处理后,组织中平均颗粒尺寸为98.6μm,平均颗粒形状因子为1.6,半固态组织分布均匀。半固态组织演变分为3个阶段:Mg17Al12相的溶解,高溶质区域的熔化,固相颗粒的球化和长大。AZ91D magnesium alloy chips were used to prepare semi-solid billet by hot pressing and semisolid isothermal treatment.The microstructure homogeneity and evolution of the semi-solid billet during reheating were investigated by OM and SEM.The results indicate that under the hot pressing parameters,the density of hot-pressed billet can reach 1.76g/cm^3,and the relative density reaches 98%.In the pressing process,the grains with obvious deformation characteristics are refined remarkably and distributed uniformly.Through semi-solid isothermal treatment,average diameter of particle is 98.6μm with average shape factor of 1.6,and the semi-solid microstructure exhibits very uniform.There exist three stages during reheating to semi-solid state：the dissolution of Mg17Al12,the melting of the region with high content of solute,and spheroidization and growth of solid particles.

关 键 词：镁合金屑 半固态组织 均匀性 组织演变 

分 类 号：TG146.22[一般工业技术—材料科学与工程] TG249.26[金属学及工艺—金属材料]