Preliminary evaluations on development of new materials for hip joint femoral head

Development and selection of a proper biomaterial with diverse properties (i.e. physical, mechanical, wear, corrosion, and many others) for hip femoral head is one of the most exigent tasks. Improper material often causes component failure during functioning. Therefore, in this study, a series of implant materials containing tungsten of different weight percentages were fabricated by high temperature vacuum casting induction furnace and the physical, mechanical, wear, and corrosion properties were examined. The proportions were varied from 0 wt% to 4 wt% in a cobalt-chromium alloy (Co-30Cr-4Mo-1Ni). The mechanical properties were tested by the micro-hardness tester and the compression testing machine, while the wear performance was analyzed through a pin-on-disc tribometer under different operating conditions at room temperature. Corrosion resistance was analyzed under NaCl solution by the electrochemical test method. Due to the conflict between the properties obtained, the Vise Kriterijumska Optimizacija Kompromisno Resenjemeaning (VIKOR) method integrated with analytic hierarchy process (AHP) was applied to choose the best material among the set of alternatives, where AHP was used to determine criteria weights, and VIKOR approach was used to rank the alternatives. From the results obtained, it was found that Co-30Cr-4Mo-1Ni implant material containing 2 wt% tungsten provides the best combination of the properties for a given application (i.e. hip femoral head).