混合方式对受控扩散凝固过共晶Al-Si合金初生硅相的影响

Effect of mixing ways on primary silicon of hypereutectic Al-Si alloys during controlled diffusion solidification

采用受控扩散凝固技术(CDS)制备Al-15%Si(质量分数)合金,研究混合方式对受控扩散凝固Al-15%Si合金初生硅相尺寸、形貌和分布的影响。结果表明:受控扩散凝固可以明显细化初生硅相,改善初生硅相形貌和在组织中的分布。其中,液-液混合细化效果比固-液混合细化效果好,特别是通过液态纯铝与液态Al-25%Si合金的液-液混合受控扩散凝固制备得到的凝固组织,其初生硅相平均尺寸仅为14μm,且在组织中分布均匀。

The controlled diffusion solidification （CDS） was used to prepare hypereutectic Al-15%Si alloy, and the effects of mixing ways during CDS process on the size, morphology and distribution of primary silicon were studied. The results show that CDS can refine the size of primary silicon obviously. Meanwhile, the morphology and distribution of primary silicon can also be improved. The effect of liquid-liquid mixing is better than that of solid-liquid mixing. Especially, the microstructure of liquid pure A1 mixing with liquid A1-25%Si alloy is the best. The particle size of primary silicon reaches up 14 um and the primary silicon distributes uniformly in the matrix.