一、前言如果将Si添加到铝合金中,将提高合金的耐磨性能并降低膨胀系数。但是,由于用熔铸法所得的过共晶Al-Si合金具有大的初始晶粒,从而恶化了热加工性能和切削性能,所以要限制Si含量。对此,在使用了急冷凝固法的粉末冶金合金中,由于初始结晶Si粒子细化分散,则提高了其热加工性能,切剥性能也有所改善。关于Al-Si系合金,将用气体喷粉法或旋转水喷粉法制成的粉末进行热挤压,对于其机械性能,已有了这方面的研究报告。然 I. Introduction If Si is added to the aluminum alloy, it will improve the wear resistance of the alloy and reduce the expansion coefficient. However, since the hypereutectic Al-Si alloy obtained by the melt casting method has large initial grains, thereby deteriorating the hot workability and the machinability, the Si content is limited. On the other hand, in the powder metallurgy alloy using the rapid solidification method, since the initial crystal Si particles are finely dispersed, their hot workability is improved, and the cutting performance is also improved. As for the Al-Si-based alloy, the powder produced by the gas atomization method or the spin-on-water method is hot-extruded, and there has been a research report on the mechanical properties of the Al-Si alloy. Of course