摘要
通过力学性能、电导率、慢应变速率拉伸试验、透射电镜及扫描电镜分析,研究了新型热机械处理对7075铝合金力学性能、抗应力腐蚀性能及显微组织的影响。结果表明:T6态合金晶内析出相细小但有粗大相存在,晶界析出相连续,具有较高的强度但塑性欠佳,抗应力腐蚀性最差;回归再时效(RRA)状态下,晶内析出相相对细小弥散,晶界析出相尺寸、间距大,具有较高的强度和抗应力腐蚀性能,塑性相对T6态有所改善;回归冷轧再时效(RRCA)态合金形变处理后产生大量位错,位错析出相及位错强化相互作用,使合金强度增大但塑性降低,晶界析出相仍为断续态,抗应力腐蚀性较好;回归热轧再时效(RRWA)工艺具有良好的综合力学性能,且抗应力腐蚀性能良好,I_(SSRT)=0.22。
Influence of thermo-mechanical treatment on tensile properties,conductivity,stress corrosion resistance（ SCR） and microstructures of 7075 alloy was studied by means of tensile test,electrical conductivity,slow strain rate testing（ SSRT）,scanning electron microscopy（ TEM） and transmission electron microscopy（ SEM） analysis. After T6 treatment,the alloy mainly contains fine precipitates,but with a few larger ones,in grains,meanwhile with continuous precipitates on grain boundaries,which shows high strength but poor plasticity and worst SCR. After RRA treatment,7075 alloy can get good distribution of matrix precipitate with discontinuous grain boundary precipitation,getting good strength and SCR compared with T6 alloy. RRCA treated alloy can obtain preferable strength because of dislocation precipitated phase and dislocation strengthening but lower plasticity; however it had better SCR because of discontinuous grain boundary precipitates. RRWA treated alloy had good comprehensive mechanical properties and good stress corrosion resistance,and its ISSRTis equal to 0. 22.
出处
《金属热处理》
CAS
CSCD
北大核心
2017年第11期97-102,共6页
Heat Treatment of Metals
基金
山东省自然科学基金(培养基金)(ZR2016EMP05)
关键词
7075铝合金
热机械处理
力学性能
应力腐蚀
7075 aluminum alloy
thermal mechanical treatment
mechanical properties
stress corrosion
