【摘要】 采用电阻炉熔炼了Al-7.2Zn-2.2Mg-1.8Cu-0.2Zr和Al-7.2Zn-2.2Mg-1.8Cu-0.2Sc-0.2Zr两种铝合金,在700~720℃挤压铸造成形,并经过465℃×24h+475℃×8h水淬+120℃×24h时效热处理。结果表明,Sc、Zr的复合添加能明显细化α-Al基体和晶间第二相;通过多级固溶和时效处理,显著提高了合金的力学性能,铸件的抗拉强度达到613MPa,屈服强度达到528 MPa,伸长率为6%。更多还原

【Abstract】 Al-7.2Zn-2.2Mg-1.8Cu-0.2Zr alloy and Al-7.2Zn-2.2Mg-1.8Cu-0.2Sc-0.2Zr alloy were prepared by resistance furnace.The two alloy samples were produced by squeeze casting at 700~720 ℃,which was treated at 465 ℃×24+475 ℃×8hsolid solution,water quenching +120 ℃×24haging.The results show that through the addition of trace element Sc and Zr,theα-Al phase and the second phase intercrystalline in the Al-Zn-Mg-Cu alloys are refined effectively.Through the multi-stage solid solution and aging treatment,the mechanical properties of alloy are improved significantly,where the tensile strength,yield strength and elongation of the samples reach up to 613 MPa,528 MPa,6%,respectively.更多还原