Survival and factorial analysis of durability and friction coefficient of a solid lubricant under different working conditions

Coatings are applied to protect surfaces subjected to fretting wear in many contacts under oscillating motions. Among these contacts, failure of the coating is a major concern. In most studies, durability and wear properties of coatings have been investigated on the coatings sliding against their metal counterfaces. However, few studies have been made on situations such that coating sliding against coating, which is common in industrial applications. In this study, research has been carried out on the fretting wear of the coating on flat or on counterbody (ball or cylinder) as well as the coating on both contacting bodies to quantify effects of coating positions (on the flat, on the ball or cylinder and on both contacting bodies) and effects of contact configuration, normal force and displacement amplitude on coating lifetime and friction coefficient. New statistical methods such as factorial analysis, regression and survival analysis have been introduced. Application of these methods allows us to take into account simultaneously effects of many experimental parameters (and their interactions) for determining friction coefficient and coating lifetime related wear mode of the coating.