On the Effect of Adhesive Strength and Scratching Depth on Material Transfer During Nanoscale Scratching

Material transfer during scratching is a direct result of adhesion and abrasive processes. In this work, molecular dynamics simulations are performed to quantify the individual effect of adhesive strength and abrasion depth on material transfer during nanoscratching of Tungsten. It is found that while the influence of adhesion and abrasion is tightly coupled at small scratching depths, the coupling decreases by increasing the scratching depth. Furthermore, it is shown that there exists a critical adhesive strength as a function of scratching depth at which the material removal mechanism transitions from the atom-by-atom to the wear fragment removal. This study confirms that the contribution of the atom-by-atom removal mechanism is suppressed when ploughing dominates the process of material removal.