热处理工艺对Al-Cu-Mn-Mg合金微观组织与力学性能的影响  

Effect of heat treatment on microstructure and mechanical properties of Al-Cu-Mn-Mg alloy

作　　者：张晗 郝启堂[1] 李新雷[1] 薛彦庆 余文涛 娄泽宇 王培卿 ZHANG Han;HAO Qi-tang;LI Xin-lei;XUE Yan-qing;YU Wen-tao;LOU Ze-yu;WANG Pei-qing(State Key Laboratory of Solidification Processing,Northwestern Polytechnical University,Xi’an 710072,China;Shaanxi Key Laboratory of Surface Engineering and Remanufacturing,Xi’an University,Xi’an 710065,China)

机构地区：[1]西北工业大学凝固技术国家重点实验室,陕西西安710072 [2]西安文理学院陕西省表面工程与再制造重点实验室,陕西西安710065

出　　处：《材料热处理学报》2023年第3期58-67,共10页Transactions of Materials and Heat Treatment

基　　金：陕西省重点研发计划(2021ZDLGY14-07);西北工业大学凝固技术国家重点实验室自主研究课题(2019-TZ-03);咸阳市秦创原科技创新专项(L2022-QCYZX-GY-017)。

摘　　要：采用扫描电镜(SEM)、透射电镜(TEM)、X射线衍射仪(XRD)、维氏硬度计和电子拉伸试验机等研究了热处理工艺对Al-5Cu-0.7Mn-0.35Mg合金微观组织和力学性能的影响。结果表明:铸态合金的微观组织主要由α-Al基体、Al_(2)Cu(θ)相、θ+T(Al_(20)Cu_(2)Mn_(3))和θ+S(Al_(2)CuMg)共晶组织构成。在固溶处理过程中,晶界处的初生θ相溶解,在后续的淬火过程中,T相析出;随着固溶温度的升高,合金的硬度曲线呈现双峰现象,随着固溶时间的延长,显微硬度先增大后减小。时效温度越高,到达峰时效的时间越短,峰值硬度越高;在时效处理过程中,显微硬度值先快速增加达到硬度峰值,之后缓慢下降逐渐趋于稳定。Al-Cu-Mn-Mg合金的最佳热处理工艺为525℃固溶处理12 h+175℃时效处理6 h,此时合金的显微硬度、抗拉强度、屈服强度和伸长率分别为145.6 HV0.2、498.2 MPa、325.4 MPa和18.5%。Effect of heat treatment on microstructure and mechanical properties of Al-Cu-Mn-Mg alloy was studied by means of scanning electron microscopy(SEM),transmission electron microscopy(TEM),X-ray diffractometer(XRD),Vickers hardness tester and electronic tensile testing machine.The results show that the microstructure of the as-cast alloy is composed ofα-Al matrix,Al_(2)Cu(θ)phase,θ+T(Al_(20)Cu_(2)Mn_(3))andθ+S(Al_(2)CuMg)eutectic structure.In the process of solution treatment,the primaryθphase at the grain boundaries dissolves and the T phase precipitates in the subsequent quenching process.With the increase of solution temperature,the hardness curve of the alloy presents a double peak phenomenon.With the increase of solution time,the microhardness of the alloy first increases and then decreases.The higher the ageing temperature,the shorter the time to reach the peak ageing,and the higher the peak microhardness.In the process of aging treatment,the microhardness value of the alloy first increases rapidly to reach the peak value,and then decreases slowly to become stable.The optimum heat treatment process of the Al-Cu-Mn-Mg alloy is solution treatment at 525℃for 12 h+aging treatment at 175℃for 6 h,and the microhardness,tensile strength,yield strength and elongation of the alloy are 145.6 HV0.2,498.2 MPa,325.4 MPa and 18.5%,respectively.

关 键 词：Al-Cu-Mn-Mg合金 热处理 微观组织 力学性能 

分 类 号：TG146.2[一般工业技术—材料科学与工程]