热循环对LF6铝合金焊接接头断裂机理的影响  

Effect of Thermal Cycle on Fracture Mechanism of LF6 Welded Joint

作　　者：金成[1] 何世禹[1] 牛济泰[1] 耿洪滨[1] 

机构地区：[1]哈尔滨工业大学材料科学与工程学院,哈尔滨150001

出　　处：《失效分析与预防》2008年第1期35-37,共3页Failure Analysis and Prevention

基　　金：国家自然科学基金(90205035)资助

摘　　要：通过模拟空间热循环试验,研究了热循环因素对LF6铝合金焊接接头断裂机理的影响。结果表明,一定时间的热循环会造成LF6铝合金焊接接头断裂机理的改变,由未经热循环时的纯剪切型断裂,逐渐过渡成微孔聚集型断裂。这是由于焊接热影响区中的聚集、析出第二相粒子的热膨胀系数与铝合金母材相差很大,热循环造成了基体与第二相之间的脱离,导致接头性能劣化和断裂机理的改变。Based on simulated aerospace thermal cycling test, the effect of thermal cycle on the fracture mechanism of LF6 aluminum alloy welded joint was investigated. The results show a certain time thermal cycle can cause the fracture mechanism change. It varies from original pure shear fracture to microvoid coalescence fracture gradually. This is because the big difference between the base aluminum alloy and the inclusions in the weld as well as the second phase particles in the heat affected zone. The thermal cycle can induce the debonding between the base alloy and second phase particles, which results in the performance deterioration and fracture mechanism varying of the welded joint.

关 键 词：冷热循环 LF6铝合金 焊接接头 断裂机理 

分 类 号：TG407[金属学及工艺—焊接]