Al-12Si-6Cu-1.5Ni-0.3Cr-0.2La-0.8Ce合金双级固溶处理工艺研究

Two-stage solid Solution Treatment Process of Al-12Si-6Cu-1.5Ni-0.3Cr-0.2La-0.8Ce Alloy

以Al-12Si-6Cu-1.5Ni-0.3Cr-0.8Ce-0.2La铸造耐热铝合金为研究对象,对其进行双级固溶处理,以及人工时效。通过OM、SEM观察以及拉伸性能测试等手段,研究不同二级固溶温度和时间对合金显微组织和力学性能的影响。结果发现,随二级固溶温度升高和固溶时间延长,合金初生Si相钝化,共晶Si和网状相溶断成颗粒状或块状,室温和高温抗拉强度呈先增加后降低的趋势,当二级固溶温度达到530℃,时间为2h时综合性能最好。对试样进行200℃×6h的时效处理,并进行室温和高温(300℃)拉伸试验,结果表明,当合金经过490℃×2h+530℃×2h+200℃×6h热处理后,室温抗拉强度达342.0MPa,高温抗拉强度达到159.9MPa。

The effects of different solid solution time and temperature on the structure and mechanical properties of the Al-12Si-6Cu-1.5Ni-0.3Cr-0.8Ce-0.2La cast heat-resistant aluminium alloy were investigated by OM,SEM observation and tensile test.It is found that with the increase of secondary solution temperature and time,the primary silicon phase is passivated,and eutectic silicon and reticular phase are fused into granular or massive,and the tensile properties of Al-12Si-6Cu-1.5Ni-0.3Cr-0.8Ce-0.2La alloy are increased firstly and then decreased at room temperature and high temperature,reaching the optimum level with the secondary solid solution at 530 ℃for 2 h.With artificial aging at 200 ℃ for 6 h,and the tensile tests at room temperature and high temperature(300℃),the tensile strength of Al-12Si-6Cu-1.5Ni-0.3Cr-0.8Ce-0.2La alloy reaches 342.0 MPa at room temperature and 159.9 MPa at high temperature(300℃)after 490℃×2 h+530℃×2 hand 200℃×6 hheat treatment.