自润滑高耐磨含铋过共晶硅铝合金的均质化制备研究

摘要

The hypereutectic aluminum-silicon alloy with Bi element is an optimal friction material of self-lubricating performance. However, its monotectic reaction will cause the gravity segregation of Bi phases in the microstructures severely. A concept of lay-by-lay solidification continuous casting with high temperature gradient was offered and an experimental device was fabricated, therefore the problem of gravity segregation of Bi phases in the microstructures was solved. The experiment results showed that the Bi phases were well-distributed finely in hypereutectic aluminum-silicon alloy, which featured the self-lubricating performance with low friction coefficient.%含铋高硅铝合金是一种具有自润滑特性的优异摩擦副材料,但它的偏晶反应导致在制备中产生严重的比重偏析.为此提出了高温度梯度逐层凝固的概念,并设计制造了高温度梯度逐层凝固连铸试验装置,解决了含铋偏晶合金最难克服的比重偏析问题,实现了铋相在过共晶铝硅合金均匀弥散分布,在过共晶高硅铝合金高耐磨的特性上增加了低摩擦系数的自润滑特性.