摘要
利用超音速火焰喷涂方法制备出NiCr/Cr3C2和NiCr/Cr3C2-BaF2.CaF2两种涂层,观察了两种涂层的组织,测定了两种涂层在650℃和800℃下的摩擦磨损性能,进而分析了BaF2.CaF2共晶相对涂层的润滑减摩作用,讨论了两种涂层的适用范围。结果表明,NiCr/Cr3C2-BaF2.CaF2涂层在800℃展现出优异的耐磨自润滑效果,摩擦系数最低,仅为0.2644,磨损率也较小,为5.88×10-6mm3/(N.m);而NiCr/Cr3C2涂层在650℃的磨损率更小,仅为3.66×10-6mm3/(N.m)。两种涂层在不同温度下表现出不同的摩擦磨损机制:NiCr/Cr3C2涂层在650℃和800℃均表现为典型的粘着磨损,但在650℃时有疲劳迹象,在800℃时则发生严重塑性变形;NiCr/Cr3C2-BaF2·CaF2涂层在650℃以磨粒磨损为主,在800℃时,由于氟化物润滑膜的作用,仅发生轻微的粘着剥落。
Two coatings, NiCr/Cr3C2 and NiCr/Cr3C2-BaF2 · CaF2, were prepared by means of high velocity oxy-fuel spraying （HVOF）. After that, by observing the microstructure and detecting the friction wear performances of the two coatings, the lubricating and friction-lessen role which BaF2 · CaF2 eutectic played in the coating were analyzed. In addition, the applica- ble range of two coatings was discussed as well based on the experimental result. It is found that NiCr/Cr3 C2-BaF2·CaF2 coating which got the lowest friction coefficient （0. 2644） and lower wear rate （5.88×10-6 mm^3·N^-1·m^-1）, possessed excellent wear-resistant and self-lubricating performances at 800 % ; The most antiwear coating is NiCr/Cr3C2, which had the even lower wear rate, only 3.66×10^-6 mm3/N·m. The coatings behaved differently under two temperatures on friction and wear mecha- nisms. Typical adhesive wear dominated in NiCr/Cr3C2 coating under both temperatures. Besides, the coating was found some signs of fatigue at 650℃, while severe plastic flow at 800℃. In contrast, the main abrasion mode of NiCr/Cr3 C2-BaF2·CaF2 coating was the micro-cutting wear at 650℃, and only some minor adhesive spalling occurred on the surface at 800℃ due to the function of the fluoride film.
出处
《表面技术》
EI
CAS
CSCD
北大核心
2012年第6期10-13,17,共5页
Surface Technology
