时效时间对触变成形AZ63合金组织及力学性能的影响  

Effects of Aging Time on Microstructures and Mechanical Properties of Thixoformed AZ63 Magnesium Alloy

作　　者：张金雨[1] 陈体军[1,2] 张素卿[1] 王博[1] 王儒亮 

机构地区：[1]兰州理工大学有色金属新材料省部共建国家重点实验室,兰州730050 [2]兰州理工大学有色金属合金及加工教育部重点实验室

出　　处：《特种铸造及有色合金》2015年第8期833-837,共5页Special Casting & Nonferrous Alloys

基　　金：教育部新世纪优秀人才培养计划资助项目(NCET-10-0023);兰州理工大学红柳杰出人才培养计划资助项目

摘　　要：研究了触变成形AZ63镁合金经不同时效时间处理后,组织及其力学性能的变化。结果表明,触变成形AZ63镁合金具有优良的时效强化效果,析出β相的分布位置、数量、形态随时效时间不断变化。连续析出相具有优异的弥散强化作用,而不连续析出相产生相反的作用。时效处理能够明显提升合金的抗拉强度和硬度,但伸长率有所下降。经过215℃时效处理2h后,抗拉强度达到最大值,为348MPa;硬度值(HV)在时效8h时达到最大,为69。与触变成形相比分别提高了53%和26%。断口形貌呈现明显的准解理特征。Effects of aging time on microstructures and mechanical properties of thixoforged AZ63 magnesium alloy were invstiagted.The results indicate that aging time affects the precipitation sites,volume fraction and shape of aging precipitation,and finally affects the mechanical properties and fracture behavior.The improvement of mechanical properties is attributed to the dispersion strengthen of continuous precipitation,and the decrease of mechanical properties is resulted from the harmful discontinuous lamellar precipitation.With the aging time increase,the fracture mode is transformed from intergranular into transgranular fracture.With aging at 215 ℃ for 2h,the tensile strength reaches 348 MPa,and hardness reaches 69（HV）with aged for 8h.Comparing with thixoforged AZ63 alloy,the tensile strength and hardness of the aged alloy are increases by 53% and by 26%,respectively.The fracture morphology is characterized by quasi-cleavage fracture.

关 键 词：触变成形 AZ63镁合金 时效时间 力学性能 微观组织 

分 类 号：TG146.22[一般工业技术—材料科学与工程] TG249.9[金属学及工艺—金属材料]