热处理对7075铝合金应力腐蚀及断口形貌的影响  

Effect of heat treatment on stress corrosion behavior of 7075 aluminum alloy

作　　者：刘继华[1,2] 李荻[2] 刘培英[2] 

机构地区：[1]上海工程技术大学材料工程学院,上海201620 [2]北京航空航天大学材料科学与工程学院,北京100083

出　　处：《材料热处理学报》2010年第7期109-113,共5页Transactions of Materials and Heat Treatment

摘　　要：采用预裂纹双悬臂梁(DCB)试样研究了7075铝合金的应力腐蚀行为。结果表明,四种不同热处理状态合金的应力腐蚀敏感性由高向低的排列顺序为T6>G180>RRA>T7351。不同热处理状态的7075铝合金试样在干燥空气中的SSRT拉伸断口形貌都是由韧窝剪切台阶组成,属于韧窝型延性断裂。在3.5%NaCl溶液中,应力腐蚀敏感性较高的T6状态铝合金,其断口形貌是由塑性韧窝和腐蚀平坦区组成的,而应力腐蚀敏感性较轻微的7075-G180铝合金,属韧性断裂。The stress corrosion behavior of 7075 aluminum alloy in different tempers was studied using double cantilever beam（DCB） specimens.The results show that the stress corrosion susceptibility of 7075 aluminum alloy decreases according to the sequence of temper T6 G180 RRA T7351.In dry air,SEM observation of the fracture surface of 7075 alloys in different temper conditions was performed and it is found the ductile fracture pattern composed of dimples and tearing ridge prevails.However,in 3.5% NaCl solution,the fracture of 7075-T6 alloy with high stress corrosion susceptibility exhibits the characteristics of flat corrosion zones and ductile dimples,but the fracture pattern of 7075-G180 alloy with moderate stress corrosion susceptibility presents ductile fracture.

关 键 词：热处理 7075铝合金 应力腐蚀 

分 类 号：TG156.91[金属学及工艺—热处理] TG172.9[金属学及工艺—金属学]