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研究铜含量对Al-Si-xCu(x=2%,3%,4%and5%)合金的微观组织和硬度的影响。不同铜含量的铝合金经熔炼后于690°C铸造成湿砂模并固化,于500°C保温7h进行固溶处理后对样品进行水冷。随后于190°C进行时效处理,分别保温5,10和15h,研究时效时间对基体硬度的影响。采用差热分析法,在冷却速度30K/min下确定平衡相的转变温度,并研究铜含量对四元共晶合金的形成和α(Al)+Si熔点的影响。结果表明,随着铜含量的增加,发生析出硬化从而导致基体硬度增加,α(Al)+Si的熔点降低,共晶相的含量增加。当铜含量超过2%时,生成熔点为507°C的四元共晶相。
The effects of copper content on the microstructure and hardness of Al-Si-xCu (x = 2%, 3%, 4% and 5%) alloys were investigated. Different copper content of the aluminum alloy after casting at 690 ° C cast into wet sand mold and cured at 500 ° C heat 7h for solution treatment after the sample was water-cooled. After aging at 190 ° C for 5, 10 and 15 h, respectively, the effect of aging time on the hardness of the matrix was investigated. Differential thermal analysis was used to determine the transition temperature of the equilibrium phase at a cooling rate of 30 K / min. The effect of copper content on the formation of the eutectic alloy and the melting point of α (Al) + Si was also investigated. The results show that with the increase of copper content, precipitation hardening occurs and the matrix hardness increases. The melting point of α (Al) + Si decreases and the eutectic phase content increases. When the copper content exceeds 2%, a tetragonal eutectic phase with a melting point of 507 ° C is formed.