【摘要】 在非真空条件下，采用普通卧式压铸机制备了Al-9Si-0.6Fe-0.2Mn-0.2Mg-0.6Cu-0.3Sc-x Zr(x=0,0.1,0.2,0.3，质量分数，%)合金拉伸试样，并采用金相显微镜、扫描电镜、电子探针和电子万能材料试验机等手段研究了其铸态显微组织和力学性能。结果表明，Zr的加入增强了合金的组织细化和变质效果，合金的抗拉强度、伸长率和硬度值均随Zr含量的增加呈现先升后降的趋势。当加入质量分数为0.2%的Zr时，合金中初生α-Al相细化效果最好，由花朵状转变成细小的枝晶状；共晶Si相变质效果也达到最佳，由蠕虫状转变为颗粒状相；合金的铸态抗拉强度、伸长率和硬度（HV）达到最大值，分别为289.3 MPa、4.9%和114.3，拉伸断裂方式为韧性断裂。更多还原

【Abstract】 Tensile specimens of Al-9Si-0.6Fe-0.2Mn-0.2Mg-0.6Cu-0.3Sc-xZr(x= 0,0.1,0.2,0.3, mass fraction, %) were prepared by horizontal die casting machine under non-vacuum conditions. The as-cast microstructure and mechanical properties of the alloy were investigated by metallographic microscope, scanning electron microscope, electron probe and electronic universal material testing machine. The results indicate that Zr addition can enhance the structure refinement and modification of alloy, and the tensile strength, elongation and hardness of the alloy is increased firstly and then decreased with the increase of Zr content. When 0.2%Zr is added, the primary α-Al phase has optimal refining effect, which is transformed from flower-like to fine dendrite. The eutectic Si phase also achieves desirable modification effect, which is transformed from worm-like to granular phase. The tensile strength, elongation and microhardness of as-cast alloy reach the maximum value, which are 289.3 MPa, 4.9% and 114.3 HV, respectively, and the tensile fracture mode is characterized by ductile fracture.更多还原