Si、Mg含量及合金元素对A356合金力学性能的影响

Effects of Si and Mg Content and Alloying Elements on Mechanical Properties of A356 Alloy

研究了Si、Mg含量及合金元素对A356合金力学性能的影响。结果表明,在A356合金中,Si元素和Mg元素在允许范围内适当增加添加量,能促使更多的Mg2Si生成,增加了共晶Si数量,合金在铸态和T6态的力学性能都有一定程度提高;在此基础上添加合金元素,初生α-Al能得到更有效细化,共晶硅变质更充分,合金的力学性能有了极大提高。高Si、Mg含量的A356合金对细化变质处理更加敏感,T6处理后力学性能达到最佳,抗拉强度和伸长率达到320MPa和8.0%,分别比低Si、Mg含量合金提高了18.6%和35.6%。

Effects of Si and Mg content and alloying elements on mechanical properties of A356 alloy were investigated.The results show that with increasing in Si and Mg content in a permissible range,mechanical properties of as-cast and T6 treated A356 alloy are improved to some extent,which is attributed to Si and Mg promoting the more creation of Mg2Si phase and increasing the numbers of eutectic phase.Furthermore,with adding alloying element,the mechanical properties of the alloy are greatly improved as a result of more effective refinement of primary Al phase and more full modification of eutectic Si phase.A356 alloy containing high Si and Mg element exhibits more sensitive to refinement and modification,tensile strength and elongation of T6 treated alloy reach up to 320MPa and 8.0%,respectively,increased by 18.6% and by 35.6%,respectively,compared with those of T6 treated alloy with low Si and Mg element.