Publication

Abstract : The research aims to fabricate LM25 alloy and composites reinforced with 15 wt% TiB 2 , 15 wt% ZrO 2 and 15 wt% WC using squeeze casting technique. The fabricated cylindrical castings were of dimensions 50 mm diameter and 150 mm length. Microstructural analysis revealed better distribution of reinforcement particles for each composite, which provided better hardness and tensile properties. Physical and wear properties were studied comparatively to understand the influence of reinforcements, and tungsten carbide (WC)-reinforced composites showed better performance. Fractographic analysis revealed ductile mode of failure for LM25 and a combination of ductile and brittle mode for its composites. Dry sliding performance of both alloy and composites was analysed under different sliding conditions of applied load (10–50 N), slide distance (500–2500 m) and slide velocity (1–5 m/s) using pin-on-disc tribometer. WC-reinforced composite improved resistance to wear by 70% compared to alloy. Wear analysis of composite using scanning electron microscope showed change in wear features from mild to severe at high loads. The developed LM25/WC composite was found to be most suitable for non-lubricated slide applications. © 2019, The Indian Institute of Metals - IIM.