Physical properties of F75 (Co-Cr-Mo Alloys) mixed with Hydroxyapatite (HAP) for Biomedical devices

Abstract

F75 (Co-Cr-Mo alloys) is primarily used in situations where strength, stiffness and fatigue endurance are required in biomedical devices. The physical properties of F75 mixed with stearic acid (binder) and varies percentage of hydroxyapatite (HAP) were studied and analyzed. The binder is used to bond the mixture. Meanwhile HAP is added to produce chemical similarity with the mineral portions of hard tissues. F75, binder and HAP were mixed and roll milled to homogenize it before pressed using uniaxial press at 500 MPa to produce green body. The green bodies then sintered in the tube furnace with argon atmosphere at 1100˚C at the rate of 20˚C / min for 120 minutes sintering time. Bulk density, apparent porosity, macrohardness and microstructure analysis were carried on the sintered products. The results revealed that bulk density of sintered product is inversely proportional to apparent porosity as expected. Bulk density and macrohardness decreased while the percentage of HAP increased. SEM was used to analyze the microstructures.