Fabrication of Magnesium-Hydroxyapatite composites targeted for biodegradable implant application

Abstract

In the present study, as a lightweight metal with mechanical properties similar to natural bone, magnesium is gaining wide popularity as biodegradable materials targeted for temporary implant applications. The objective of the present work is to fabricate magnesium based metal matrix composites (MMC) for degradable implant applications and hydroxyapatite (HA) powder was selected as the secondary phase. The samples magnesium-hydroxyapatite was prepared by using powder metallurgy technique and conventional sintering. Conventional sintering of the milled powders resulted in the formation of structure of magnesium with the presence of hydroxyapatite. Temperature was selected as the third phase for magnesium-hydroxyapatite (Mg-HA) composites of 600°C, 620°C, and 640°C were fabricated using powder metallurgy and conventional sintering. Density and porosity of the composites investigated by densimeter machine with increase the temperature and the best density is found for the Mg-HA (640°C) composite which is 1.4519 g/cm³. This composite also exhibits maximum Vickers hardness. Young's modulus and fracture toughness measured by indentation method were higher for the Mg-HA (640°C) composite which is 159.08 MPa.m½. Besides, this composite also exhibits maximum compressive strength and the best compressive strength is found for the Mg-HA (640°C) with a value 99.6054MPa. The results thus suggest that structured Mg-HA composites with 640°C sintering temperature show Mg-HA (640°C) promise for temporary degradable orthopedic implant applications because of their improved physical and mechanical properties.