Spark Plasma Sintered Hydroxyapatite – Zirconia Composites: Structural and Mechanical Properties

Hydroxyapatite (Ca10(PO4)6(OH)2) (HAp) is a very attractive material for human tissue implantation, beacuse it makes up ~69% of the weight of bone [1]. Unfortunately HAp posses low mechanical properties (strength, fracture toughness), which is a barrier to its applications in load-bearing situations [2]. The mechanical properties of HAp composites, is based on the synthesis of composites and the second phase. As the second phase is yttria stabilized zirconia (ZrO2) exhibits high toughness and has wide applications in bone surgery, because it is classified as a bioinert ceramic [3, 4]. Advanced sintering methods as spark plasma sintering (SPS) eliminated the regular problem, that during the sintering process HAp decomposed due to the applied high temperature [4]. SPS is capable for sintering ceramic powders fast to a high density at relatively low temperatures [4].