Development and characterization of Al2O3 –HAP composite by Powder Metallurgy for biomedical applications

Abstract

In this study , Alumina (Al2O3) and hydroxyapatite (HAP) composite were prepared by using powder metallurgy (PM) technique of vacuum sintering. As alumina non osteoinductive its bio- inertness did not allow bone ingrowth. To obtain a novel material for load bearing biomedical applications with relatively low lower modulus, adequate strength as well as excellent biocompatibility Alumina (Al2O3) and hydroxyapatite (HAP) composite that possess bio inertness and biocompatibility have been developed. For proper characterization purpose four compositions of the composite were prepared with Alumina concentration of 60,70,80 and 90 percent and Hydroxyapatite concentration of 40,30,20 and 10 percent of the two total volume. Powders were mixed by using Ball Mill and Cold compacted by using hydraulic press. The green pellets were vacuum sintered at 1300°C and 1350 °C for 2,3 and 4 hours of dwell time . Then all samples grinded and polished for characterization. Micostructure of the samples was analyzed by scanning electron microscope and optical microscope to onserve the uniformity of powders distribution and densification. Moreover density and micro hardness test were carried out to assess the mechanical strength of the sintered samples. According to research results, mechanical properties of the composites are increased by increasing the concentration of Al2O3 and decreased by increasing the amount of HAP. And the composition with 70% alumina and 30% of hap was considered as best for biomedical applications when it is sintered at 1350°C for four hours.