V对A380铝合金显微组织和力学性能的影响

Effects of V on Microstructure and Mechanical Properties of A380 Aluminum Alloy

研究了金属型重力铸造下不同V含量的A380合金的显微组织和力学性能。结果表明,在铸态下,A380合金添加V元素后生成了一种不规则块状的AlSiVFe相。随着V含量增加,AlSiVFe相的平均长度由15μm增至43μm,体积分数从0.3%增至1.65%,长针状β-Al_5FeSi相平均长度由47μm减至24μm。T6热处理后合金的相组成不变,富Fe相形态无明显变化,纤维状共晶Si转变为粒状或球状。随着V含量增加,铸态和T6态合金的力学性能均呈先增大后减小的趋势。当V含量为0.7%时,合金力学性能最优,T6态下其抗拉强度为244MPa,屈服强度为226MPa,伸长率为1.6%。

The microstructure and mechanical properties of A380 alloy fabricated by gravity casting with different V contents were investigated.The results show that with V addition,irregular block-like AlSiVFe phase can be observed in the alloy.With the increase of V content,the average length of AlSiVFe phase is increased from 15μm to 43μm,and the volume fraction is increased from 0.3%to 1.65%.The average length ofβ-Al5 FeSi phase is decreased from 47μm to 24μm.The phase constitution of the alloy is absent change after T6 treatment.The morphology of the Fe-rich phases has no obvious change after heat treatment.However,the fibrous eutectic Si phase is changed into granular particles.With the increase of V content,mechanical properties of the as-cast or heat-treated alloy are increased at first and then decreased.When the V content is 0.7%,the mechanical properties of the alloy reach the maximum value,where tensile strength,yield strength and elongation of the heat-treated alloy reach 244 MPa,226 MPa and 1.6%,respectively.