Hydroxyapatite Dispersed Magnesium-Based Composite Produced from Pulverized Magnesium Alloy Powder and Its Mechanical Properties

A magnesium matrix composite made of Mg–1mass%Ca and 10 vol% hydroxyapatite (HAp) particles was synthesized. The alloy powder was processed by pulverization of the small blocks of the alloy ingot using a high–speed blade grinder. Unreacted composite was successfully produced by extruding the two component powders at a temperature of 538 K. In the extruded composites, the grains of the magnesium matrix were equiaxed and the matrix grain size was 3.9 μm. As for the HAp particles, both thin clustering and severe agglomeration with the size of ~30 μm were observed. The Young's modulus, tensile yield strength and tensile strength of the extruded composite were 39 GPa, 101 MPa and 153 MPa, respectively. The damping capacity of the composite was higher than that of extruded magnesium. The composite also showed good forgeability at a temperature of 523 K. However, quite high impurity contents of Fe (0.130 mass%) and Ni (0.010 mass%) were introduced in the magnesium matrix of the composite, probably as a result of contamination that accumulates during the processing (pulverization) of the alloy powder. [doi:10.2320/jinstmet.J2017036]