摘要
对缎铝ＬＤ７ 以变形温度、变形速率和对材料的预处理方式为三因素，按正交设计进行高温拉伸试验，寻找最佳的超塑性条件． 经过淬火＋ 过时效＋ 温变形处埋，在５３０ ℃， ε＝ ２－７８ ×ｌ０ － ４ｓ－ １ 时，呈现出显著的超塑性，延伸率达２６０ ％ ； 而挤压状态和经过温变形处理后，在适当的变形条件下，材料都具有较好的塑性；正交试验分析结果表明：变形温度是影响ＬＤ７ 铝合金超塑性最显著的因素；显微观察表明：ＬＤ７ 铝合金由于第二相粒子的作用，具有稳定的微细组织结构，因而其超塑性效应明显。
In the paper the superplastic of LD7 aluminium alloy was studied with special pre-tretment.Total elongation as high as 260% can be achieved under the follow condition: 530 ℃ and 2 78×l0 -4 s -1 . The superplastic (δ≥100%)of LD7 aluminium alloy can also be achieved without special pretretment under sone condition. The study proved that temperature is most importain condition for LD7's superplasticity. In high temprature forming process, the grain become axle with re-crystalling process and the presence of particles of second phases leads to the formation of fine and stable grans necessary for achieveing superplasticity.
