Surface observations of a powder layer during the damage process under particulate lubrication

► The process and mechanism of powder layer damage is investigated. ► Bonding between the powder layer and the bottom sample is weak. ► Shearing and sliding of the powder layer accommodated the speed difference. ► Micro-damages include blistering, delamination, detachment and scuffing. ► The whole life cycle consist of full powder layer, partial detachment, serious detachment, and complete destruction.