微量Mg元素对Al-Si-Cu合金铸件组织及力学性能的影响  

Influence of Trace Mg on the Microstructure and Mechanical Properties of Al-Si-Cu Alloy Castings

作　　者：杨兴国 YANG Xingguo(Intelligent Manufacturing and Automotive Institute,Chongqing Technology and Business Institute,Chongqing 401520,China)

机构地区：[1]重庆工商职业学院智能制造与汽车学院,重庆401520

出　　处：《汽车实用技术》2023年第17期128-133,共6页Automobile Applied Technology

基　　金：重庆市教育委员会科学技术研究项目(KJQN202004005);重庆工商职业学院重点科研项目(NDZD2020-02)。

摘　　要：针对发动机气缸体因力学性能差引起热机异响故障问题,文章结合优化调整工艺参数、改进模具浇注及冷却系统方案、增加热处理工艺等有效降低铸件缩孔、缩松率、提高铸件气密性的措施,重点研究了微量Mg元素对铸态Al-Si-Cu合金组织及力学性能的影响。结果表明,Mg在含量0.05%~0.55%范围内,随着Mg含量的增加,组织中存在于共晶Si和基体Al交界处的强化相Mg2Si逐渐增加;当Mg含量大于0.3%时,铸件的抗拉强度和屈服强度分别达到230.6MPa和157.3MPa,提升了43.6%和69.9%,实际应用中可以确定Mg含量为0.3%~0.55%,以确保铸件具有稳定的力学性能,避免诱发其他机械故障。In view of the abnormal noise of the engine cylinder block caused by the mechanical properties of the engine,the paper took measures to optimize the process parameters,improve the mold casting system and increase the heat treatment process,and studied the effect of trace Mg elements on the organization and mechanical properties of cast Al-Si-Cu alloy.The results show that in the range of Mg content from 0.05%to 0.55%,the mechanical properties of the castings show an increasing trend with the increase of Mg content,and the strengthening phase Mg2Si,which exists in the junction of eutectic Si and matrix Al in the organization,gradually increases;when the Mg content is greater than 0.3%,the tensile strength and yield strength of the castings reach 230.6 MPa and 157.3 MPa,respectively,raising the Mg content can be determined to be 0.3%~0.55%in practical applications to ensure that the castings have stable mechanical properties and thus avoid inducing other mechanical failures.

关 键 词：Mg元素 AL-SI-CU合金 铸件组织 力学性能 

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]