微量Al变化对压铸Mg-4Sm-2Al合金组织和性能影响  

Effects of Trace Variation of Al Content on Microstructure and Properties of HPDC Mg-4Sm-2Al Alloy

作　　者：李子昕 陈滨 童胜坤 陆仕平 梁晟 胡波 付彭怀[1] 彭立明[1] 李德江[1] 曾小勤[1] LI Zixin;CHEN Bin;TONG Shengkun;LU Shiping;LIANG Sheng;HU Bo;FU Penghuai;PENG Liming;LI Dejiang;ZENG Xiaoqin(National Engineering Research Center of Light Alloy Net Forming,School of Materials Science and Engineering,Shanghai Jiaotong University,Shanghai 200240;Wanfeng Meridian Lightweight Technology Co.,Ltd.,Shaoxing 312580)

机构地区：[1]上海交通大学材料科学与工程学院,轻合金精密成型国家工程研究中心,上海200240 [2]万丰镁瑞丁新材料科技有限公司,绍兴312580

出　　处：《特种铸造及有色合金》2025年第2期161-165,共5页Special Casting & Nonferrous Alloys

基　　金：国家重点研发计划资助项目(2021YFB3701000);国家自然科学基金资助项目(52301059,52271009)。

摘　　要：采用压铸工艺制备了SA42和Mg-4Sm-2.6Al(SA42.6)合金,分析了微量Al含量变化对合金力学性能的影响。结果表明,在SA42合金的基础上添加0.6%(质量分数,下同)的Al后,合金屈服强度和伸长率分别降低了10.2%和63.5%。这是因为Al与基体内固溶的Sm反应形成了大量的大块Al_(2)Sm相,使得合金基体内固溶的Sm浓度降低了近50%,导致固溶强化效果大幅降低。形成的Al_(2)Sm相带来的第二相强化和晶界强化效果无法弥补固溶强化效果的缺失,导致了SA42.6合金的屈服强度比SA42合金的低了近20 MPa。伸长率大幅降低主要归因于Al_(2)Sm颗粒与基体的模量不匹配,Al_(2)Sm颗粒较脆较硬,在变形过程中产生了较大的应力集中,加速了合金的断裂失效。SA42 and Mg-4Sm-2.6Al(SA42.6)alloys were fabricated by HPDC process,and influence of trace Al content on mechanical properties was systematically analyzed.The results indicate that with 0.6%Al addition to SA42 alloy,the yield strength and elongation are reduced by 10.2%and 63.5%,respectively,which is attributed to the large quantities of massive Al_(2)Sm phases generated by reaction between Al and Sm dissolved into the matrix,leading to an approximate 50%reduction in Sm concentration within Mg matrix,significantly diminishing solute strengthening effects.The contributions from secondary phase strengthening as well as grain boundary strengthening provided by formed Al_(2)Sm can hardly compensate for the loss in solid solution strengthening effect,resulting in an approximate reduction of 20 MPa in yield strength for SA42.6 compared to that of SA42.The substantial decrease in elongation pri⁃marily arises from modulus mismatch between Al_(2)Sm particles and Mg matrix.The brittle and hard Al_(2)Sm particles induce great stress concentrations during deformation processes,thereby accelerating fracture and failure.

关 键 词：MG合金 力学性能 压铸 组织 

分 类 号：TG249.2[金属学及工艺—铸造] TG146.21[一般工业技术—材料科学与工程]