Evaluation of Mechanical, Microstructure and Sliding Wear Characteristics of Different Al-Zn Alloy and Composite: A Comparative Research

Abstract

Plain bearings are extensively used in many engineering application. The wear loss of bearing material is the one of the major parameter that affects the performance of bearing. In this investigation, four Al-25Zn alloy samples reinforced with silicon carbide and graphite content were fabricated using stir casting technique. The mechanical properties, microstructure and sliding wear characteristics of fabricated specimens were studied. Dry sliding wear characteristic of specimens was investigated using a pin on disc tribometer with EN24 shaft steel disc at three speeds 1.0472m/s, 2.0944m/s and 3.1416m/s and three different applied pressures 0.3747MPa, 0.7584MPa and 1.1421MPa as per Taguchi L9 orthogonal array. The microstructure examinations of the worn surfaces were carried out using a scanning electron microscope (SEM). The hardness, tensile strength and wear resistance of Al-25Zn alloy with the addition of silicon carbide particles is found to be increased. The addition of graphite particles in Al-25Zn alloy enhances the wear resistance and tensile strength of the composite, in spite of the substantial decrease of hardness. The worn surfaces show the presence of delamination and abrasive wear mechanisms in the localized region.