摘要
采用金相显微分析、扫描电镜和能谱分析等手段,研究了80 mm厚超高强Al-6.4Zn-2.3Mg-2.1Cu铝合金热轧板经第一级470℃以及第二级480℃固溶处理前后的相和组织的演变。结果表明,该合金热轧板中主要存在粗大块状的Al2Cu Mg相、长棒状Al7Cu2Fe相及含Zn Mg Cu的细小析出相等,经470℃固溶处理5 min后,Zn Mg Cu析出相基本溶入基体,90 min后完全溶入基体。经470℃1.5 h+480℃5 h双级固溶处理后存在极少量未溶Al2Cu Mg相,板材组织仍为部分再结晶组织,晶粒总体轮廓与热轧态的相似;随第一级470℃及第二级480℃固溶时间的延长,该合金厚板晶粒形态变化较小,沿轧制方向伸长且部分晶粒中存在细小亚晶组织,亚晶尺寸随固溶时间延长而缓慢长大。
The phase and microstructure evolution of ultra-high-strength rolled plates of Al-6.4Zn-2.3Mg-2.1Cu aluminum alloy with 80mm thickness was studied before and after the 470℃ ＋480℃ two-stage solution treatment by the metallographic microscopic analysis, the scanning electron microscopy and the energy spectrum analysis. The results show that coarse massive A1ECuMg phases,long rod-like Al7Cu2Fe phases and tiny ZnMgCu precipita- ted phases originally exist in these rolled plates. The tiny ZnMgCu precipitated phases gener- ally dissolve into the matrix after the solution treatment of 470℃ 5min, and totally dissolve after 90min. After the 470℃ 1.5h ＋ 480℃ 5h two-stage solution treatment, a very tiny amount of undissolved Al： CuMg phases exist, the plate structure is partial recrystallization, and the grain contours are similar to those in the hot-rolled state. With time increase of the 470℃ ＋ 480℃ two-stage solution treatment ,the grain shape changes slightly, the plate is ex- tended along the rolling direction, tiny subgrains exist in some grains and they grow up slowly with the solution time goes on.
出处
《轻合金加工技术》
CAS
北大核心
2015年第1期27-32,共6页
Light Alloy Fabrication Technology
