时效处理对7075铝合金组织及性能的影响  

Effects of Aging Treatment on Microstructure and Properties of 7075 Aluminum Alloy

作　　者：刘书潭 邹龙江[1] 黄一川 李绍威 LIU Shutan;ZOU Longjiang;HUANG Yichuan;LI Shaowei(School of Materials Science and Engineering,Dalian University of Technology,Dalian 116133,China;Dalian Huicheng Aluminum Co.,Ltd.,Dalian 116100,China)

机构地区：[1]大连理工大学材料科学与工程学院,辽宁大连116133 [2]大连汇程铝业有限公司,辽宁大连116100

出　　处：《热加工工艺》2023年第16期154-158,共5页Hot Working Technology

摘　　要：对T6态7075铝合金进行了双级时效和回归再时效(RRA)处理,采用SEM及XRD分析其微观组织,使用硬度测试和拉伸试验进行力学性能对比,测得极化曲线和交流阻抗以研究其耐蚀性。结果表明,相对于T6态铝合金,双级时效后的铝合金强度、硬度下降,但其伸长率提高;回归再时效处理后,合金的硬度上升至179.8 HV,屈服强度上升至509.5 MPa,抗拉强度为561 MPa,伸长率保持不变。回归再时效处理后的合金自腐蚀电位与双级时效态的自腐蚀电位接近,高于T6态合金,回归再时效态合金的自腐蚀电流密度为3.3151μA/cm2,仅为T6态合金的1/2左右;其等效电阻远高于T6态合金。以上结果表明,回归再时效处理提高了合金的韧性和耐蚀性,同时保持了较高强度和硬度。The T6 state 7075 aluminum alloy was treated by double stage aging and regression aging(RRA)treatment.The microstructure was analyzed by SEM and XRD.The mechanical properties were tested by hardness test and tensile experiment.The electrochemical methods were used to study the corrosion behavior by test the polarization curve and AC impedance.The experimental results show that,compared with the aluminum alloy in the T6 state,the hardness and the strength of the aluminum alloy after double stage aging decreases,but its elongation rate increase.After the regression and re-aging treatment,the hardness of the alloy increases to 179.8 HV,the yield strength increases to 509.5 MPa and the tensile strength is 561 MPa and the elongation remaines constant.The self-corosion potential of the alloy after RRA treatment is close to the self-corrosion potential of the double stage aging state,which is higher than the T6 state alloy.The self-corrosion current density of the RRA state alloy is 3.3151μA/cm²,only about 1/2 of the T6 alloy,and its equivalent resistance is much higher than that of the T6 alloy.The above results indicate that RRA treatment improves the toughness and corrosion resistance of the alloy,while maintaining the higher strength and hardness.

关 键 词：7075铝合金 回归再时效(RRA) 力学性能 腐蚀性能 

分 类 号：TG166.3[金属学及工艺—热处理]