Green Synthesis of Hydroxyapatite Powder from Eggshell Biowaste for Enhanced Mechanical and Corrosion Properties in AZ91 Alloy Composites: A Powder Metallurgy Investigation

This study presents the development of hydroxyapatite (HAp) powder synthesized from eggshell bio- waste, with a subsequent investigation into its reinforcement in AZ91 alloy using powder metallurgy. Mechanical and corrosion properties of the resulting metal matrix composites (MMCs) were evaluated. The MMCs containing 18% HAp demonstrated twice the hardness of those with 0% HAp. Moreover, the MMCs with 0% HAp displayed four times greater weight gain and three times greater weight loss in simulated marine water compared to the 18% HAp MMCs. In conclusion, HAp-reinforced AZ91 alloy composites exhibit adjustable mechanical and corrosion properties.