Numerical analysis of pin on disc tests on Al-Li/SiC composites

It is well known that metal matrix composites exhibit marked improvements in wear resistance when compared to unreinforced alloys. In operating conditions, components made of Al-based composites are usually subjected to elevated temperatures and high contact loads. In this work, an experimental programme on a pin on disk test on Al-Li/SiC metal matrix composite and the corresponding unreinforced alloy was carried out at different loads and temperatures. A finite element model to simulate wear tests was also developed. The sliding distance of the pin was discretized in several steps according to the input velocity. Wear is taken into account updating the geometry of the pin in every step. The material worn out in each step is computed using the Archard law and the normal pressure acting on the contact surface. The nodes of the contact surface were displaced in the normal direction and the geometry and the finite element mesh of the pin were automatically updated. The model includes some other important features such as Coulombic friction, temperature-dependent plasticity behaviour of the pin, heat generation at the contact surface by plastic deformation of the pin. Thermo-mechanical coupled equations resulting in every step were integrated using Abaqus Standard code.