铜含量对近共晶Al-11.6Si合金组织与性能的影响

Effects of Cu content on microstructure and properties of near eutectic Al-11.6Si alloy

在近共晶Al-11.6Si合金中,添加不同含量的铜,通过对比合金的组织、流动性、耐腐蚀性、力学性能等参数,研究铜含量对近共晶Al-11.6Si合金组织与性能的影响,确定合金中铜的最佳添加量。研究表明,随着铜含量的增加,合金中Al2Cu相体积分数不断增加,尺寸不断增大;合金流动性呈现递增的趋势;腐蚀电流密度和腐蚀速率不断增大,耐腐蚀性能逐渐下降;合金抗拉强度呈现先增大后减小的趋势,当铜含量为3%时,合金铸态和T6热处理后的抗拉强度达到最大值,分别为257 MPa、330 MPa,伸长率则不断减小。

After adding different percents of Cu, the microstructure and properties of near eutectic Al-11. 6Si alloys were investigated by comparing microstructure, fluidity, corrosion resistance and mechanical properties, so as to determine the appropriate content of Cu in this alloy. The results show that with the increase of Cu content, the volume and size of Al2 Cu phase increase, the fluidity, corrosion current density and corrosion rate of the alloy increase, but corrosion resistance decreases. The tensile strength of the alloy sharply increases until addition of 3%Cu and then slowly decreases, the highest tensile strength of as-cast and T6 heat treated alloy reaches 257 MPa and 330 MPa, respectively, while the elongation decrease.