变形速率对半固态AlSi7Mg合金变形性的影响

来源期刊：中国有色金属学报2000年第z1期

论文作者：张大辉 毛卫民 钟雪友

文章页码：132 - 134

关键词：半固态铝合金； 变形性； 形变速率

Key words：semi solid aluminum alloy； deformation behavior； deformation rate

摘    要：采用Gleeble-1500热模拟机对半固态AlSi7Mg合金触变压缩过程中的变形性进行了研究。结果表明 ,当保温时间为10～30s,变形温度为 579℃时 ,随着形变速率提高 ,试样内部最大抗力及最大应力皆呈上升趋势。应变率较小时 ,变形的主导机制由液相流动和阻尼液相流动渐变为颗粒滑动和颗粒塑性变形 ;应变率较大时 ,应力变化可分为三阶段 ,即瞬态激增段、平稳变化段及稳定变化段。瞬态激增段的变形机制由初始的液相流动和阻尼液相流动骤变为颗粒滑动和颗粒塑性变形 ,其它两个阶段为 4种变形机制交互作用。

Abstract: The deformation behavior of the semi solid AlSi7Mg alloy was studied using the Gleeble-1500 thermal simulator. When the deformation temperature is at 579 ℃, the holding time is 10 to 30 s, the inner maximum resistance force and the maximum stress of the specimen decreases with increasing deformation rate. At smaller deformation rate, the deformation mechanisms change from liquid flow(LF) and flow of liquid incorporating solid particles(FLS) into sliding between solid particles(SS) and plastic deformation of solid particles(PDS). At higher deformation rate, the sudden change stage is dominated by four mechanisms, the stable stage is dominated by LF and FLS mechanisms, the gradual increasing stage is dominated by SS and PDS mechanisms.