【摘要】 研究了Al5TiB、RE对Mg 8Zn 4Al 0.3Mn铸造镁合金显微组织的影响.结果表明:Mg 8Zn 4Al 0.3Mn铸造镁合金的显微组织主要由Mg相、(Al2Mg5Zn2)相和τ(Mg32(Al,Zn)49)相组成.加入Al5TiB、RE变质剂,合金晶界上三元相的形态由半连续网状改变为颗粒状,三元相的分布逐渐变得弥散而均匀,且可以显著细化合金的铸态组织,晶粒大小由120～130μm减少到30～50μm.更多还原

【Abstract】 The effects of Al5TiB and RE on microstructure of Mg-8Zn-4Al-0.3Mn casting magnesium alloys have been studied. The results show that casting microstructures of Mg-8Zn-4Al-0.3Mn magnesium alloys mainly contain Mg matrix, eutectic α（Mg）,（Al₂Mg₅Zn₂）phase and τ(Mg₃₂（Al,Zn）₄₉) phase. The morphology of ternary phases on the grain boundaries changes from quasi-continuous net to particle and the distribution of ternary phases gradually changes dispersively and homogeneously by addition of Al5TiB and RE. Casting microstructures of Mg-8Zn-4Al-0.3Mn magnesium alloys can be refined by addition of Al5TiB and RE, and the size of grains decreases from 120～130μm to 30～50μm.更多还原