A study on mechanical behavior and wear performance of a metal–metal Co–30Cr biomedical alloy with different molybdenum addition and optimized using Taguchi experimental design

Molybdenum-added biomedical alloy has been prepared using a high-temperature vertical vacuum casting technique with five (0, 1, 2, 3, and 4 wt%) diverse weight percentages. The density, microhardness, and sliding wear behavior of the fabricated alloys were studied, showing that the addition of molybdenum content in the metal–metal alloy (i.e., Co–30Cr) increases the density from 7.2 to 8.7 g/cc for 0–4 wt% of Mo, respectively. Similarly, the hardness of prepared biomedical alloy also increases from 653 to 720 HV on addition of 0–4 wt% Mo particulate, respectively. The hardness is investigated by the microhardness tester. The aim of this current research work is to optimized the sliding wear behavior of molybdenum-added Co–30Cr alloy for implant material by Taguchi experimental design technique at five different normal loads (5–25 N), sliding velocities (0.26–1.3 m/s), sliding distance (500–2500 m), and reinforcement, i.e., Mo (0–4 wt%) respectively. To obtain the optimum wear response of prepared biomedical alloy added with Mo contents, the Taguchi L25 orthogonal array was implemented. The wear test is performed on a pin-on-disc tribometer against a hardened alloy steel (EN-31) disc under different operating conditions at room temperature. Afterwards, field-emission scanning electron microscopy and atomic force microscopy were utilized to analyze the microstructure, contour of wear mechanism, and 3D surface topography of samples after test run.