摘要
通过光学显微镜(OM)、X射线衍射分析(XRD)、扫描电镜(SEM)及力学性能测试等方法,研究了微量Sr(0、0.015%、0.03%,质量分数,下同)对砂型铸造Al-Si-Mg合金微观组织及力学性能的影响。结果表明,微量Sr的加入能显著细化铸态合金中粗大共晶Si及二次枝晶尺寸,但超过0.015%后,合金含气量增多。铸造Al-Si-Mg合金主要由Al相、Si相及少量的Mg2Si相、Al3Ti相、Al-Fe-Si相组成,加入微量Sr没有形成Al4Sr相。随着Sr含量增加,合金的抗拉强度逐渐提高,伸长率先升高后降低。Sr含量为0.015%时,合金具有最佳的力学性能,其在铸态、时效态的抗拉强度和伸长率分别为156 MPa、4.55%和349 MPa、3.07%。继续增加Sr含量,含气量的增加导致合金伸长率迅速降低。
The effects of Sr(0,0.015%,0.03%,mass fraction)on the microstructure and mechanical properties of Al-Si-Mg alloy were investigated by means of OM,XRD,SEM and mechanical property test.The results indicate that the addition of trace Sr(0,0.015%,0.03%)elements can significantly refine the size of coarse eutectic silicon and secondary dendrites in as-cast alloy,while gas content of the alloy is increased with Sr exceeding 0.015%.The as-cast alloy is mainly composed of Al phase,Si phase and a small amount of Mg2Si phase,Al3Ti phase and Al-Fe-Si phase,and absence of new phase is observed with trace Sr addition.With the increase of Sr content,the tensile strength of alloy is increased gradually,and the elongation is firstly increased and then decreased.The optimal mechanical proper⁃ties are achieved with Sr content of 0.015%,where the tensile strength and elongation of the as-cast and as-aged alloys are 156 MPa,4.55%and 349 MPa,3.07%,respectively.The elongation is decreased rapidly with Sr content increas⁃ing due to the increase of gas content.
作者
邹斌
梁秋贤
苏再军
刘胜强
沈克新
陈卓夫
欧玲
ZOU Bin;LIANG Qiuxian;SU Zaijun;LIU Shengqiang;SHEN Kexin;CHEN Zhuofu;OU Ling(Guizhou Honglin Aerodynamic Control Technology Co.,Ltd.,Guiyang 550009;Guangdong Huihuang Metal Products Co.,Ltd.,Zhaoqing 526200;College of Intelligent Manufacturing,Guangzhou Vocational College of Technology and Trade,Guangzhou 511442;College of Materials and Advanced Manufacturing,Hunan University of Technology,Zhuzhou 412007)
出处
《特种铸造及有色合金》
北大核心
2025年第5期750-753,共4页
Special Casting & Nonferrous Alloys
基金
广东省普通高校重点领域专项资助项目(2023ZDZX3076)
广州市教育局羊城学者科研资助项目(2024312443)。
