等离子喷涂纳米和常规喂料WC-Co涂层在干摩擦和水环境中的摩擦磨损性能研究

Friction and Wear Behavior of WC-Co Coatings Sprayed by Nanoscale and Conventional Powders in Dry and Water Environment

采用大气等离子喷涂法分别以纳米和常规喂料制备出2种WC-Co涂层,在SRV摩擦磨损试验机上考察了2种涂层在干摩擦和水环境中的摩擦磨损性能.结果表明:在干摩擦和水环境中,纳米WC-Co涂层的摩擦系数和磨损率均小于常规WC-Co涂层;纳米和常规WC-Co涂层的磨损机制差异不大,在干摩擦下其磨损机制主要以粘着磨损、剥落和磨粒磨损为主;在水环境中,WC-Co涂层与S i3N4配副时的摩擦系数和磨损量较与不锈钢球配副时高,2种摩擦副的磨损机理有所不同,前者主要以剥落和疲劳磨损为主,后者主要以粘着磨损为主,伴有轻微的磨粒磨损.

Atmospheric plasma spraying method was used to deposit nanoscale and conventional WC-Co coatings using nanostructured WC-Co powder and conventional WC-Co powder as feedstock, respectively. Tribology properties of the coatings was investigated on a SRV under dry and water environment. Results indicate that the friction coefficient and wear rate of nanoscale coating was lower than conventional coating mostly, the wear mechanism of both coating was similar. The wear mechanism when rubbed against steel ball was mainly adhesion, brittle fracture abrasive in dry friction. In water environment, the wear of the coating was controlled by brittle flake with fatigue abrasion. When Si3N4 ball was replaced by steel ball in water environment, the friction and wear rate was effectively reduced, the wear mechanism was mainly adhesion with some abrasive. Nanoscale WC-Co coating exhibits better tribology performance than conventional coating both in dry friction and water environment. In water environment, the friction and wear can be effectively reduced when rubbing against steel ball.