【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。更多还原

【Abstract】 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.更多还原