摘要
研究了不同热处理工艺下7A55铝合金淬火预拉伸(W51)板材的力学性能、腐蚀性能、电导率变化以及相应的微观组织特点。用正交实验分析双级时效工艺,结果表明7A55铝合金双级时效的四因素中第二级时效温度和时间是影响最终性能的主要因素。淬火预拉伸7A55合金板材最佳双级时效热处理工艺分别为:T7651:121℃×5h+170℃×6h,T7451:121℃×5h+160℃×14h。电镜观察结果表明,T7451、T7651时效时晶内析出半共格的η′相和η相,并有不同程度粗化,晶界为断续分布的粗大η平衡相。这种微观结构能有效的提高7A55合金板材的电导率和腐蚀性能,同时使合金具有较高强度。
Effects of aging treatment on tensile properties,corrosion resistance,electrical conductivity and microstructure of pre-stretched（W51）7A55 alloy plate were investigated.The orthogonal test results show that the second step aging temperature and time are the key factors in double aging parameters,which mainly decide the final properties of 7A55 alloy.The optimized double aging treatment of 7A55 alloy pre-stretch plate are as follows：T7651：121 ℃ × 5 h ＋ 170 ℃ × 6 h,T7451：121 ℃ × 5 h ＋ 160 ℃ × 14 h.The TEM observation results show that semi-coherent η＇ and η precipitates in matrix,and the coarse and isolate precipitations in grain boundaries in T7451 and T7651 tempers,contribute to improved corrosion resistance and electrical conductivity of the alloy.
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
2010年第11期128-133,共6页
Transactions of Materials and Heat Treatment
基金
中国铝业公司科技发展基金项目(CHINALCO-2007-KJ-03)
关键词
7A55铝合金板材
双级时效
剥落腐蚀
正交实验
电导率
7A55 alloy plate
double aging
exfoliation corrosion（EXCO）
orthogonal test
electrical conductivity
