Effect of Heat Treatment on Mechanical properties of Aluminium metal matrix composite (AA6061/MoS2)

Abstract

ABSTRACT This paper emphasises an experimental investigation on the mechanical properties of molybdenum disulphide (MoS2) powder reinforced in aluminium alloy (AA6061-T6) composite. MoS2 (1% 2%, 3%, 4% and 5% by weight) powder of approximately 2-μm particle size was reinforced in an aluminium alloy matrix (AA6061) to produce aluminium metal matrix composites (AMMCs) through stir casting technique. The fabricated AMMC specimens were solutionised at 540°C for 1 hr and quenched immediately in cold water and then artificially aged at 180°C for 12 hrs. The treated AMMCs are subjected to a series of tests to evaluate the mechanical properties such as hardness, tensile strength, % elongation and flexure strength and then compared with as-cast composites and matrix material (AA6061). Optical microscopy, scanning electron microscopy and X-ray diffraction analysis were carried out to analyse the microstructure and the dispersion of the reinforced particles in the composite and alloy. It was observed from the results that, the hardness, tensile strength and flexure strength increased with the increase in weight % of reinforcement whereas % elongation and flexural strain decreased with increase in % weight of reinforcement particles in the composite up to 4% addition of reinforcement and on further addition of reinforcement in the matrix decreased the properties- Abbreviations: AA 6061: Aluminium alloy 6061 with T6 temper designation (matrix material); MoS2: Molybdenum disulphide (reinforcement material); AMMCs: Aluminium metal matrix composites; MMCs: Metal matrix composites; SEM: Scanning electron microscopy; HT: Heat treatment; HV: Vickers hardness; XRD: X-ray diffraction