Investigation of Al-Mg based composite incorporated with MoS2 through powder metallurgy

Abstract

In this study, powder metallurgy process has been utilized to produce the composite materials. Pure aluminium (Al) has been selected as the matrix material for the preparation of composite materials. 4% of magnesium (Mg) has been added as the alloying element, whilst molybdenum disulphide (MoS2) is reinforced with a varying wt.% (2, 4 & 6). The intent of this work is, to evaluate some basic mechanical properties (density, microhardness, compression strength and toughness), surface degradation properties (corrosion and wear), and electrical conductivity of the fabricated composite materials. Moreover, SEM mapping and EDAX analysis have been conducted to confirm the presence of reinforcement particles with homogenous distribution in the matrix material and to do the fractographic study of the compressive strength tested samples. The density of the composite material Al-4% Mg-6%MoS2 has been increased compared to the density of pure Al material. Micro Vickers hardness test shows that Al-4% Mg-6%MoS2 composite has 32.86% more hardness as compared to that of pure Al material. Compressive strength of the composite material with the higher wt.% of MoS2 is found to be 181.81 N/mm2, while Al material has only 167.52 N/mm2. The buckling formation during the compression test is avoided in the composite material owing to the existence of MoS2 particulates. The wear loss of composite materials is found low as compared with the unreinforced Al material, owing to the solid lubricant property of MoS2 particles, and hence, coefficient of friction (COF) is also lessened with the increase in the MoS2 wt.%. Also, the MoS2 reinforced materials show good resistance to corrosion due to the presence of molybdenum, which acts as a consistent layer obstacle to prevent the surface from further degradation.