Sc对Al-Zn-Mg-Cu系铸造铝合金组织与性能的影响

摘要

研究了添加x％Sc (x=0.15,0.30,0.45)对Al-6.0Zn-2.8Mg-1.9Cu试验铝合金金属型铸造组织和室温及200～300℃高温力学性能的影响.研究表明,Sc可以有效改变合金基体α(Al)相的尺寸和形态,并对合金共晶组织有明显的变质作用,同时可以有效去除合金组织中的Al7Cu2Fe含铁相,从而提高试验合金的室温抗拉强度.当Sc添加量为0.45％时,合金的室温抗拉强度最高可达510MPa.但Sc对合金的室温塑性影响不大.当Sc添加量为0.30％时,合金的高温瞬时抗拉强度明显提高.%Effects of x% Sc (x=0.15, 0.30, 0.45) addition on the microstructures and mechanical properties of metal mold casting aluminum alloy Al-6.0Zn -2.8Mg-1.9Cu were studied. The results show that addition of Sc can reduce α( Al) grain size, modify α( Al )+η(MgZn2) eutectic of the experimental alloy, and eliminate Al7Cu2Fe phase effectively. The addition of Sc element can improve the room temperature ultimate tensile strength of the experimental alloy, but has little effects on its plasticity. The room temperature UTS of the experimental alloy with the addition of 0.45% Sc reach 510 MPa, the maximum value, among the three Sc-content alloys. In addition, the high temperature tensile strength of the experimental alloy with addition of 0.30% Sc increased apparently comparing those with 0.15% and 0.45% Sc.