Fabrication of hydroxyapatite coated magnesium alloy for orthopedic bio-degradable metallic implant applications

Abstract

Magnesium (Mg) and its alloys are potential biodegradable implant materials because of their alluring biological property. Moreover, they have attracted growing interest as a promising alternative for medical implant and device applications due to their advantageous mechanical and biological properties. However, the major limitation of magnesium is its rapid degradation in physiological fluids and low corrosion resistance property which might lead to failure of implants. Therefore, the present key challenge lies in controlling Mg degradation rate in physiological environment. The objective of this thesis was to fabricate Hydroxyapatite on magnesium alloy for orthopedic biodegradable implant operations. Hydroxyapatite (HA) is a calcium phosphate bio ceramic material that has nearly identical properties to that of the mineral component of bone. Its osteoconductivity and biocompatibility have led to its application in a broad range of applications in orthopedics and dentistry. The present work aims to deposit Hydroxyapatite (HA) on magnesium AZ31using electrode position technique to enhance the bio-degradable property of magnesium implant material. The morphology of the coatings were studied using SEM-EDS and FTIR characterizations and optical microscopy. The biodegradable nature of HA coatings were examined by electrochemical tests. Post treatment of HA coating is required to convert the amorphous phases into complete HA. The experimental results signified that HA coatings after post treatment in alkali solution 1M NaOH can slowdown the biodegradation rate of AZ31 magnesium alloy in Phosphate Buffered Saline (PBS).