中文摘要：

以AZ91D镁合金建筑刮板为例,将自行开发的锥桶式流变成形机（TBR）与TOYOBD-900V4-T冷室压铸机相结合实现了流变压铸成形工艺过程.研究了不同流变成形工艺下压铸件的组织特征,分析了成形过程中浆料的组织形成机理及凝固行为.结果表明：该流变成形工艺可以获得内部组织细小、初生α-Mg晶粒呈近球形或球形且分布均匀的成形件.当内锥桶转速为700r.min-1时,压铸件内部组织较圆整、均匀,平均晶粒尺寸约45μm,形状因子约0.81.流变压铸过程中合金熔体的凝固主要经历了一次凝固和二次凝固两个阶段.

英文摘要：

Take an AZ91D alloy architectural scraper for example,the rheo-diecasting process was implemented by combining a self-developed taper barrel rheomoulding （TBR） machine with a TOYO BD-900V4-T cold chamber die-casting machine.The microstructural characteristics of the components were investigated in different rheo-diecasting processes,and the microstructure formation and solidification behavior of the semi-solid slurry were analyzed.The results show that the process is able to obtain components in which the primary α-Mg particles are fine,spherical or nearly spherical and uniformly distributed.The microstructure of rheo-diecasting components is relatively round and homogeneous when the rotation speed is 700r·min-1.The primary α-Mg particles have an average size of about 45 μm and a shape factor of about 0.81.Solidification of the alloy melt taking place in the rheo-diecasting process is composed of two distinct stages：primary solidification and secondary solidification.