Mg和Cu对铸造Al-Si-Cu-Mg合金组织与性能的影响

Effect of Cu and Mg on Microstructure and Properties of Al-Si-Cu-Mg Alloy

通过OM、SEM、T6热处理、拉伸性能测试等方法,研究了Cu、Mg等合金元素对Al-Si-Cu-Mg合金微观组织与力学性能的影响。研究表明,Al-Si-Cu-Mg合金中,Al_2Cu和Q-Al_5Cu_2Mg_8Si_6是主要强化相。Cu、Mg含量增加可以很大程度提高Al-Si合金的强度,但合金的伸长率会降低。经T6(520℃×10 h固溶+170℃×6 h时效)热处理,Al-Si-Cu-Mg合金的强度与韧性均有所提高,当Cu/Mg为4时,抗拉强度、屈服强度及伸长率分别达到426.7 MPa、294.9 MPa和6.3%。

The effects of Cu, Mg and other alloy elements on microstructure and mechanical properties of Al-Si-Cu-Mg alloy were investigated by means of OM, SEM, T6 heat treatment and tensile test. The results show that A12Cu and Q-A15Cu2Mg8Si6 are the main reinforcing phases in Al-Si-Cu-Mg alloys. The increase of Cu and Mg can greatly improve the strength of A1-Si alloy, but the elongation of alloy will decrease. After T6 （520 ℃ ×10 h solid solution＋170 ℃×6 h aging） heat treatment, Al-Si-Cu-Mg alloy strength and toughness are improved. When the Cu/Mg is 4, tensile strength, yield strength and elongation are 426.7 MPa, 294.9 MPa and 6.3%, respectively.