Fabrication and multi- performance optimization of mechanical properties of novel Babbitt-Ilmenite metal matrix composite using entropy based hybrid Taguchi-grey relational analysis

Abstract

Abstract In the present study, a Babbitt-Ilmenite composite was developed via stir casting and the mechanical properties (hardness and tensile strength) of the composite were optimized using the Taguchi philosophy. The effects of variations in the percentage weight of Ilmenite, stirring speed and aging time on the mechanical properties of the composite were studied. Energy dispersive spectroscopy analysis confirmed the presence of Ilmenite in the metal matrix and uniform dispersal of Ilmenite in Babbitt was established via scanning electron microscopy. A Morphological analysis of the fractured tensile specimen was conducted to ascertain the type of failure. The Taguchi methodology and analysis of variance technique were proposed to predict the optimum levels of controllable parameters and to determine their percentage contribution to the optimization of mechanical properties of the composite. The percentage weight of Ilmenite and stirring speed were found to have significant effect on hardness while aging time was a significant parameter for the tensile strength of the composite. The predicted results were validated by confirmation experiments with a deviations of 1.6% and 2.1% for hardness and tensile strength respectively for single objective optimization. The weights of the responses were determined objectively and the multi-performance optimization of mechanical properties of the composite was performed using entropy based grey relational analysis (EGRA). The percentage weight of Ilmenite was only significant parameter with contribution of 30.65% for multi-performance optimization of mechanical attributes of composite using hybrid Taguchi grey relation analysis (TGRA). An overall improvement of 0.445 and 0.105 in the grey relation grade was reported using EGRA and TGRA respectively. The study concludes that the Babbitt/Ilmenite composite has superior mechanical properties both for single and multi-objective optimized conditions than the unreinforced tin Babbitt. The developed composite can be used for bearings in crankshafts, connecting rods and axles of automobiles.