Fabrication of Titanium-Matrix Composite with 40 wt% Hydroxyapatite by Powder Injection Molding

In this work, the performance of composites feedstock HA/Ti for metal injection molding is investigated by rheological characterization with powder loading 65%. Titanium and Hydroxyapatite (HA) powder are mixed with a composite binder, which consists of Palm Stearin (PS) and Polyethylene (PE). The rheology properties are investigated by Shimadzu CFT-500D rheometer. Thermal debinding is utilized for removing the binder system under argon gas. The sintering process is performed under argon conditions at temperature 1200 °C for 2 h. The feedstock 60 wt%Ti and 40 wt%HA show pseudopalstic behaviour which is indicating suitable for MIM application. On the sintered part, Ca:P ratio of HA has changed based on the standard value of HA(1.67) as an indication decomposition of HA. Cracks have been observed on part of composite HA/Ti by SEM due to differences in thermal expansion of the two materials and not a good diffusion between HA and Ti. For further work, modification in the composition of mixture and sintering parameters are required to reach an optimal result.