7050铝合金的蠕变行为研究  

Creep Behavior of 7050 Aluminum Alloy

作　　者：徐显强 董显娟[1] 徐勇 涂泽立 鲁世强[1] 龚思恒 Xu Xianqiang;Dong Xianjuan;Xu Yong;Tu Zeli;Lu Shiqiang;Gong Siheng(School of Aeronautical Manufacturing Engineering,Nanchang Hangkong University;Jiangxi Hongdu Aviation Industry Group Co.,Ltd.)

机构地区：[1]南昌航空大学航空制造工程学院,南昌330063 [2]江西洪都航空工业集团有限公司

出　　处：《特种铸造及有色合金》2023年第6期825-830,共6页Special Casting & Nonferrous Alloys

基　　金：航空科学基金资助项目(2020Z047056003);江西省重点研发计划资助项目(20202BBEL53012)。

摘　　要：通过恒应力单轴蠕变拉伸试验,研究了7050铝合金在温度为121~177℃,外加应力为170~250 MPa范围内的蠕变拉伸行为,分析了蠕变温度和外加应力对蠕变拉伸行为的影响。结果表明,外加应力在170~250 MPa应力范围内,7050铝合金在温度为121℃和149℃时具有优良的低温抗蠕变性能。通过扫描电镜(SEM)观察断口形貌,发现蠕变断裂机制随应力的增加由典型的韧窝断裂向准解理-韧窝混合断裂转变。计算了表观应力指数n、蠕变激活能Q,表明随着蠕变温度的升高和外加应力的增大,蠕变机制可能由晶界扩散控制的位错黏性滑移机制转变为第二相粒子控制机制。The creep tensile behavior of 7050 aluminum alloy at temperature of 121~177 ℃ and applied stress of 170~250 MPa was investigated by constant stress uniaxial creep tensile test.The influence of creep temperature and stress on creep tensile behavior was analyzed.The results indicate that 7050 aluminum alloy possesses excellent low-temperature creep resistance at 121 C and 149 C in the stress range of 170~250 MPa.SEM observation reveals that the creep fracture mechanism is converted from typical dimple fracture to mixture of quasi-cleavage and dimple fracture with the increase of stress.The apparent stress index(n)and creep activation energy(Q)were computed,demonstrating that the creep mechanism may be transformed from the cohesive slip mechanism controlled by grain boundary diffusion to that controlled by second phase particles with the increase of creep temperature and applied stress.

关 键 词：7050铝合金 蠕变 应力指数 激活能 蠕变机制 

分 类 号：TG146.21[一般工业技术—材料科学与工程]