铝硅合金潜热变化规律的DSC分析

通过真空电弧炉制备不同Si质量分数的铝硅合金,利用差示扫描量热分析仪测量合金的潜热,分析了Al-Si合金的成分与潜热之间的相互关系。结果表明,Al-Si合金初生相和共晶相的潜热需要进行单独求解,在Si的质量分数为4.16％～21.4％范围内,Al-Si合金潜热随Si的质量分数增加呈线性增加,亚共晶潜热、过共晶潜热具有不同的线性关系,分别为:L_hypo=353.4+12X(亚共晶)和L_hyper=409.6+7.54X (过共晶),其中X为Si的质量分数;过共晶Al-Si合金中初生Si相的潜热与纯Si的潜热相差较大是由Al-Si熔体中与纯Si熔体中Si的形态差异引起的。

DSC analysis for latent heat of the aluminum-silicon alloy

The latent heat of Al-Si alloy, prepared by vacuum arc furnace and with different Si content, was studied by differential scanning calorimeter (DSC). The results indicate that the latent heat of the primary phase and the eutectic phase should be computed independently, the latent heat of the alloy increased with the mass fraction of Si increasing from 4.16％ to 21.4％, and the linear relationship of the latent heat of the hypoeutectic alloy and the hypereutectic alloy was different, which were L_hypo=353.4+12X and L_hyper=409.6+7.54X. It was also found that it was the different forms of Si in Al-Si melt and the pure Si melt that caused the different latent heat of the Si phase in different melt.