ABSTRACT The solidification behaviour of hypereutectic Al–Si alloy melts at 70°C above the liquidus with different Si contents between 27 and 50 wt% and cooling rates from 50 to 300°C/min were studied using a confocal laser scanning microscope (CLSM). It was found that the primary Si size and surface roughness decreased while the wear resistance improved with higher cooling rates and lower Si contents. An interesting result showed that the hardness and wear resistance changed in an opposite direction with increase of Si content. The causes of the improvement of wear resistance are mainly attributed to a decreasing primary Si size and the corresponding surface roughness.

中文翻译：

---

不同Si含量和冷却速度的过共晶Al-Si合金的初生Si相演化、表面粗糙度和力学性能

摘要 使用共聚焦激光扫描显微镜 (CLSM) 研究了过共晶 Al-Si 合金在液相线以上 70°C 下的凝固行为，不同的 Si 含量介于 27 至 50 wt% 之间，冷却速率为 50 至 300°C/min。 . 结果表明，随着冷却速率的提高和硅含量的降低，初生硅尺寸和表面粗糙度降低，而耐磨性提高。一个有趣的结果表明，随着硅含量的增加，硬度和耐磨性向相反的方向变化。耐磨性提高的原因主要归因于初级硅尺寸的减小和相应的表面粗糙度。