Dry tribological behavior of hot-rolled WE43 magnesium matrix composites reinforced by B4C particles

Abstract

This study aims to develop a novel hot-rolled WE43-B4Cp composite with improved tribological performance for employment in the automotive industry. The pin-on-disc tribometer was used to evaluate the dry tribological behavior of newly developed composite materials containing (0-10) wt.% B4C under various applied loads. It was observed that increasing B4C content reduced the friction coefficient and significantly improved wear resistance in composite samples, especially at higher applied loads. With the addition of 10 wt% B4C, the wear resistance of WE43 alloy was improved by around 25% at low load and 50% at high load regimes. The surface morphology and topography of the wear tracks were examined to identify the dominant wear mechanisms in each wear condition and reinforcement content. The dominant wear mechanisms at low loads were abrasion and slight oxidation, which were switched to adhesion and delamination as the applied load increased and thus to severe plastic deformation under high loads. The superior wear performance of the hot-rolled WE43-10%B4Cp composite was ascribed to improved hardness and strength, as well as increased work hardening capacity of subsurface due to the presence of hard and thermally stable B4C particles with uniform dispersion and proper bonding to the matrix.