半固态5083铝合金压缩变形行为及组织特性

Compressive Deformation Behavior and Microstructure Characteristics of Semi-solid 5083 Aluminum Alloy

采用Gleeble 3500热模拟试验机,分别对铸态和SIMA法制备的半固态5083铝合金压缩变形行为进行了研究,并结合压缩后的宏观形貌和显微组织对液相的流动规律进行了分析。结果表明,变形温度和应变速率是影响5083铝合金半固态坯料热压缩变形的两个重要参数;在半固态温度区间压缩变形时,铸态坯料整体应力水平明显高于SIMA法制备的半固态坯料;而在固态温度区间内高温压缩变形时,二者流变应力曲线特征相似,半固态坯料没有明显优势;两种不同状态5083铝合金固液两相区压缩变形时,存在3个典型变形区域,半固态组织中液相均匀分布于晶粒晶界处,而铸态组织中液相分布位置极不均匀,半固态5083铝合金压缩变形后试样的致密度和均匀性优于铸态材料。

Compressive deformation behavior of as-cast and semi-solid 5083 alloy prepared by SIMA method was examined on the Gleeble 3500 thermo-simulator,meanwhile,flow characteristics of the liquid phase was also analyzed based on the compressed macromorphology and microstructure.The results show that deformation temperature and strain rate are closely related to the thermal compressive behavior of semi-solid 5083 aluminum alloy billets.With compressive deformation in semi-solid temperature range,the whole stress in as-cast billets is obviously higher than that in SIMA prepared ones,while with compressive deformation in solid temperature,flow stress curves of the two exhibit similar and there is no remarkable advantages for the semi-solid alloy.There exist three typical deformation regions for the two alloys during compressive deformation in the semi-solid temperature range.The liquid phase in the semi-solid alloy is uniformly distributed along the grain boundary,while its distribution exhibits relatively uneven in the as-cast alloy.The density and uniformity of the semi-solid 5083 alloy are superior to those of the as-cast alloy after hot compressive deformation.