Nb-Ti-Si-Cr基超高温合金及其表面Zr-Y联合改性硅化物渗层的摩擦磨损性能

摘要

Zr−Y jointly modified silicide coatings were prepared on an Nb−Ti−Si−Cr based ultrahigh temperature alloy by pack cementation process. The wear behaviors of both the base alloy and coatings were comparatively studied at room temperature and 800 °C using SiC balls as the counterpart. The Zr−Y jointly modified silicide coating is mainly composed of a thick (Nb,X)Si2 outer layer and a thin (Ti,Nb)5Si4 inner layer. The coatings possess much higher microhardness than the base alloy. The wear rates of both the base alloy and coatings increase with increasing the sliding loads. However, the coatings have much lower wear rates than the base alloy under the same sliding conditions. The coatings have superior anti-friction property, and can provide effective protection for the base alloy at both room temperature and 800 °C in air.%采用扩散共渗方法在Nb−Ti−Si−Cr基超高温合金表面制备Zr−Y改性的硅化物渗层，对比研究基体合金和共渗层在室温和800°C 与 SiC 球对磨时的摩擦磨损性能。所制备的 Zr−Y 改性硅化物渗层主要由较厚的(Nb, X)Si2外层和较薄的(Ti, Nb)5Si4内层组成。共渗层的显微硬度明显高于基体合金。基体合金和共渗层在常温和800°C时的磨损率均随摩擦载荷的增加而增加，但在相同的摩擦条件下，共渗层的磨损率明显低于基体合金。Zr−Y改性硅化物渗层在室温和800°C时的磨损抗力均优于基体合金，能够为基体合金提供良好的保护。