Wear-estimation law based on debris-level origins using a diamondlike-carbon head

Diamondlike-carbon (DLC) films are widely used as nanocoatings in devices such as in hard disk drives. However, the narrow spacing causes collisions between the head and disk and leads to wear of the nanocoatings. Herein, the nanoscale wear estimation approach during DLC head sliding is investigated. The molecular dynamics (MD) method is applied to create a systematic interface model that explores how the wear mechanisms of the DLC head transform. The mechanisms of wear debris formation are discussed by analyzing the corresponding spatial distributions. Based on the clear fundamental debris-level origins of the MD simulation, an improved wear law is proposed for time-resolved adhesive wear estimation at the nanoscale. The proposed law establishes a connection between the measurable quantity, that is, normal stress, and the height loss. It is applied to quantify the head's height loss and additional simulations involving different external loads are performed to verify the applicability of the proposed wear law.