【摘要】 采用Gleeble 1500热模拟试验机,对半固态铸造铝合金A356进行了半固态压缩和固态压缩实验,分析了它们的应力 应变关系·结果表明:在变形速率小于5s-1的中、低变形速率下压缩,随着变形速率的升高,流动应力增加;在变形速率大于5s-1的高变形速率下压缩,流动应力下降:随变形程度的增加,半固态压缩发生应变 软化现象;分析了半固态压缩变形过程中的几种变形机制,讨论了半固态触变过程中的金属流动特点,为半固态成形的模具设计提供理论依据·更多还原

【Abstract】 Unilateral compression tests on A356 alloy of semi-solid and solid were carried out using the Gleeble-1500 dynamic material testing machine. The relationship between the stress and strain for the semi-solid A356 alloy was established in different deformation conditions. The results show that the flow stress increase s with increasing strain rate when  is lower than 5?s-1. How ever, the stress decreases with increasing strain rate when  is hig her than 5?s-1. It decreases also with increasing the strain, that is to say, the strain softening occurs during semi-solid deformation. At last, by ana lyzing several deformation mechanisms and by discussing metal flowing characteri stic during thixoforming of semi-solid, several rules are suggested for the die design in semi-solid forming.更多还原