Influence of boron carbide content on dry sliding wear performances of AZ91D magnesium alloy

Abstract

In this study, AZ91 magnesium alloy based metal matrix composites are made-up of bottom pouring stir casting with 0 wt.%, 1.5 wt.% and 3 wt.% boron carbide (B₄C) particles reinforcements. The influence of hard reinforcements on mechanical properties such as hardness and tensile strength has been investigated for the casted composites samples. It was found that by adding 1.5 wt. % and 3 wt.% B₄C particles, the Rockwell hardness value of 3.2% and 4.6%, Ultimate Tensile Strength (UTS) values of 15.5% and 26.3% of the composites increased respectively. The influence of B₄C contents on AZ91D mg alloy wear study was carried out using pin on disc apparatus. Also, the effect of applied load (5N, 10N, and 20N) on wear properties was investigated. The results of the dry sliding wear tests show that AZ91D- B₄C magnesium composite has less wear loss than the unreinforced AZ91D magnesium alloy. X-ray diffraction (XRD) analysis were performed for finding the various compounds such as MgO, B₄C and Mg₁₇Al₁₂ present in the developed composites. Further, scanning electron microscopy (SEM) analysis were performed on the worn-out pin surfaces to investigate the wear pattern. These findings indicate that the addition of B₄C content improved mechanical characteristics and wear resistance, which may also be used in the automotive and aerospace industries.