机械搅拌法对半固态AZ91D镁合金显微组织的影响  

Effects of Mechanical Stirring Method on Microstructure of Semi-solid AZ91D Magnesium Alloy

作　　者：杨柳青[1] 康永林[1] 崔建利[1] 王朝辉[1] 

机构地区：[1]北京科技大学材料科学与工程学院

出　　处：《特种铸造及有色合金》2007年第S1期432-434,共3页Special Casting & Nonferrous Alloys

基　　金：国家重点基础研究发展计划(973计划)项目(2006CB605203)

摘　　要：利用自行开发的一种新型的半固态轻合金制备与直接流变成形装置,研究了剪切温度、剪切速率及压力等工艺对合金微观组织的影响。结果表明:剪切作用不但改变了基体相α-Mg的形态,而且改变了相的分布,即晶粒细化沉淀析出的α-Mg和β-Mg17Al12共晶组织趋向于更均匀地沿晶分布,几乎在α-Mg晶粒周围形成连续的网状结构;在高剪切速率下,半固态颗粒的形态圆整度有很大的提高,并且均匀分布在合金基体中;剪切温度低时,组织中固相率较高,且固相颗粒也较细小均匀;在半固态AZ91D镁合金冷却成形时,施加适当的压力更有利于组织细化和性能提高。Using a new semi-solid preparing and rheoforming machine which self-developed for light alloys in laboratory,researched effects on technology to alloy microstructure,such as shear temperature,shear speed rate,pressure force.The results show that shear not only changed the shape of α-Mg,but also changed distribution of the phase,namely α-Mg and β-Mg17Al12 eutectic structure due to grain refinement lixiviation tend to intergranular distribution equably,almost forming continuous mesh texture around α-Mg grain;the shape of semi-solid particles becomes regulate quietly,and average distribution in alloy body under high shear speed rate;the solid-phase rate of alloy structure becomes higher,and the solid-phase particles become also fine when shear temperature is low;when semi-solid AZ91D alloy is cooling and forming,applied to proper force make for structure refinement and advanced properties.

关 键 词：机械搅拌 半固态 AZ91D镁合金 显微组织 

分 类 号：TG249.9[金属学及工艺—铸造]