A7075搅拌摩擦焊疲劳裂纹扩展速率试验分析  

Fatigue crack growth rate of A7075 FSW

作　　者：王希靖[1] 李树伟[1] 牛勇[1] 张杰[1] 

机构地区：[1]兰州理工大学甘肃省有色金属新材料省部共建国家重点实验室,兰州730050

出　　处：《焊接学报》2008年第9期5-7,共3页Transactions of The China Welding Institution

基　　金：国家自然科学基金资助项目(10577010)

摘　　要：对航空用铝合金A7075-T651的搅拌摩擦焊接头的母材、焊核区和热影响区的疲劳裂纹扩展速率(da/dN)进行了试验研究。疲劳裂纹扩展试验采用CT(紧凑拉伸)试样,在810 Material Test System试验机上进行。用递增多项式法求得疲劳裂纹扩展速率(da/dN)和(ΔK),并分别将母材、焊核区和热影响区同一组试样的(da/dN)和(ΔK)数据点合在一起进行了整体回归分析。试验中得到了以Paris公式表达的铝合金A7075-T651母材、焊核区、热影响区da/dN与ΔK的关系式。结果表明,热影响区疲劳裂纹扩展速率高于母材和焊核区,是该合金搅拌摩擦焊接头最薄弱的区域。The fatigue crack growth rate of A7075-T651 aluminum baseplate,FSW welding and heat-affected zone were studied.And A7075-T651 aluminum baseplate were welded with FSW-3LM-015 friction stir welding machine.Fatigue crack growth tests using CT specimen and 810 Material test system for testing machine.Polynomial method obtained by increasing fatigue crack growth rate(da/dN) and(ΔK) respectively,include the base metal and welding zone and the heat-affected zone in the same sample group(da/dN) and (ΔK)combined data points overall regression analysis.Experimental results indicated fatigue crack growth rate of the heat-affected zone is higher than that of the base metal and weld the nuclear area.

关 键 词：搅拌摩擦焊 疲劳裂纹扩展速率 热影响区 A7075铝合金 

分 类 号：TG453[金属学及工艺—焊接]