The effect of nanobioceramic reinforcement on mechanical and biological properties of Co-base alloy/hydroxyapatite nanocomposite

• Co-base alloy/hydroxyapatite composites were prepared by powder metallurgy.
• Composite microhardness is improved in comparison with Co-base alloy.
• Modulus elasticity decrease by about 53–63% in comparison with Co-base alloy.
• Apatite nucleus is formed on the surface of composites after soaking test.
• Bioinert Co–Cr–Mo alloy is successfully converted to a bioactive type.

The goal of the present research was to fabricate, characterize, and evaluate mechanical and biological properties of Co-base alloy composites with different amounts of hydroxyapatite (HA) nanopowder reinforcement. The powder of Co–Cr–Mo alloy was mixed with different amounts of HA by ball milling and it was then cold pressed and sintered. X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques were used. Microhardness measurement and compressive tests were also carried out. Bioactivity behavior was evaluated in simulated body fluid (SBF). A significant decrease in modulus elasticity and an increase in microhardness of the sintered composites were observed. Apatite formation on the surface of the composites showed that it could successfully convert bioinert Co–Cr–Mo alloy to bioactive type by adding 10, 15, and 20 wt.% HA which have lower modulus elasticity and higher microhardness.

The present investigation has been based on the production of composite materials based on Co–Cr–Mo alloy with different amounts of hydroxyapatite nanobioceramic powder using the powder metallurgy route. Mechanical and biological properties of the composites were investigated. A significant increase in microhardness and decrease in modulus elasticity of the sintered composites were observed.Figure optionsDownload as PowerPoint slide