Tribological investigations on HfC reinforced AZ31 Magnesium Metal Matrix Composites

Abstract

In this paper, an attempt was made to prepare Magnesium Metal Matrix Composites (MMCs) using AZ31 Mg as matrix material and hafnium carbide (HfC) as reinforcement material. AZ31-HfC Mg MMCs were prepared by using stir casting method using different HfC reinforcement percentages such as 5%, 10% & 15% by wt. Tensile tests and surface micro hardness tests on AZ31-HfC Mg MMCs were conducted. Yield strength & ultimate tensile strength & surface micro hardness of AZ31-HfC MMCs was found to increase up to 12%, 17% & 23% compared to base material AZ31 Mg alloy. Tribological studies were conducted using three sliding speeds (2 mm/s, 4 mm/s and 6 mm/s). Micro scratch tests were conducted on traction force and coefficient of abrasive friction variations. Pin on disc wear tests were conducted to study the wear mass loss of AZ31-HfC MMCs at different loading conditions, sliding rate and reinforcement percentage of HfC by wt. SEM analysis of wear tested specimens indicated voids, furrows, micro-cracks and wear debris.