【摘要】 ADC12压铸铝合金具有良好的铸造性,广泛应用于制造工业产品。然而,一般压铸件不适合通过T6热处理来提高力学性能,特别是由于它的塑性和韧性较差,使其作为结构部件受到限制。为改善其力学性能,试验配制了两种不同Si含量的ADC12(Si1)、ADC12(Si2)合金以及添加w(Sr)=0.02%,w(Cr)=0.3%,w(Zr)=0.3%的ADC12(+)铝合金,并配合特殊固溶处理及其后的时效处理析出强化来提升压铸ADC12铝合金的力学性能。试验结果表明:由于ADC12系列铝合金在铸态下的伸长率均低于4.1%,都属于脆性材质;但经460℃(0.5～2) h固溶处理,可使ADC12(Si1)、ADC12(Si2)及ADC12 (+)三种合金的伸长率大幅提升(分别从4.1%、3.3%及4.0%提升至21.5%、23.3%及12.4%);再经过175℃8 h人工时效,三种合金的抗拉强度及伸长率分别达到420 N/mm2及8.7%、415 N/mm2及6.8%、425 N/mm2及7.6%,且添加Cr、Zr、Sr的ADC12(+)铝合金呈现较好的显微组织与力学性能。因此,大幅度扩大了ADC12压铸铝合金的应用范围。更多还原

【Abstract】 ADC12 die casting aluminum alloy has good castability and is widely used in manufacturing industrial products. However,it is not suitable to improve the mechanical properties of die castings by T6 heat treatment,especially because of its poor ductility and toughness leading to its limitations as the structural part. In order to improve the mechanical properties,ADC12( Si1) and ADC12( Si2) alloys with different Si contents and ADC12( +) aluminum alloy with Cr,Zr,Sr were prepared. The special solution treatment and subsequent aging treatment precipitation strengthening were used to improve the mechanical properties of die-casting ADC12 aluminum alloy. The results show that the elongation of ADC12 series aluminum alloy is lower than 4. 1% in as cast state,which belongs to brittle material. However,after solution treatment at 460 ℃( 0. 5-2) h,the elongation of ADC12( Si1),ADC12( Si2) and ADC12( +) alloys increase significantly( from 4. 1%,3. 3% and 4. 0% to21. 5%,23. 3% and 12. 4%,respectively). After artificial aging at 175 ℃ for 8 h,the tensile strength and elongation of the three alloys reach 420 N/mm2 and 8. 7%,415 N/mm2 and6. 8% and 425 N/mm2 and 7. 6%,respectively. The ADC12( +) aluminum alloy with Cr,Zr and Sr shows good microstructure and mechanical properties. Therefore,the application range of ADC12 die casting aluminum alloy is greatly improved.更多还原