**Abstract**

In this Chapter, a severely adhesive wear on a rough aluminum (Al) substrate is simulated by molecular dynamics (MD) under a high velocity impact of a hardasperity (a hard-tip) with the Al-asperity. Multiple simulations include effects of four factors: the inter-asperity bonding, the geometry overlap between two asperities, the impact velocity between two asperities and the starting temperature of the Al-substrate. It is observed that the deformation mechanism on the Al-substrate would involve a local melting (from 1200 to 2500 K) which forms liquid type layers (amorphous textures) in the contact area between two asperities. Also, temperature profiles on the hard-tip and the Al-substrate is depicted. Moreover, a method in the Design of Experiments (DOE) is employed to interpret above all simulations. The DOE results indicate that the inter-asperity bonding and the geometry overlap between two asperities would substantially increase the wear rate (for about 53.56% and 67.29% contributions), while the starting temperature of the Al-substrate and the impact velocity between two asperities would play less important roles (about 10.30% and 6.61%) in raising the wear rate.

**Keywords:** the wear rate, molecular dynamics, the EAM potential, the Lennard-Jones potential, the design of experiment
