HA (hydroxyapatite)/β-TCP (tricalcium phosphate) biomaterial (BCP; biphasic calcium phosphate) is widely used as bone cement or scaffolds material due to its superior biocompatibility. Furthermore, NH4HCO3 as a space holder (SH) has been used to evaluate feasibility assessment of porous structured BCP as bone scaffolds. In this study, using a spark plasma sintering (SPS) process at 393K and 1373K under 20MPa load, porous HA/β-TCP biomaterials were successfully fabricated using HA/β-TCP powders with 10~30 wt% SH, TiH2 as a foaming agent, and MgO powder as a binder. The effect of SH content on the pore size and distribution of the BCP biomaterial was observed by scanning electron microscopy (SEM) and a microfocus X-ray computer tomography system (SMX-225CT). The microstructure observations revealed that the volume fraction of the pores increased with increasing SH content and that rough pores were successfully fabricated by adding SH. Accordingly, the cell viabilities of BCP biomaterials were improved with increasing SH content. And, good biological properties were shown after assessment using Hanks balanced salt solution (HBSS).

Ceramics biomaterials are useful as implant materials in orthopedic surgery. In this study, porous HA(hydroxyapatite)/β-TCP(tricalcium phosphate) composite biomaterials were successfully fabricated using HA/β-TCP powders with 10-30 wt% NH4HCO3 as a space holder(SH) and TiH2 as a foaming agent, and MgO powder as a binder. The HA/β-TCP powders were consolidated by spark plasma sintering(SPS) process at 1000 oC under 20 MPa conditions. The effect of SH content on the pore size and distribution of the HA/β-TCP composite was observed by scanning electron microscopy(SEM) and a microfocus X-ray computer tomography system(SMX-225CT). These microstructure observations revealed that the volume fraction of the pores increased with increasing SH content. The pore size of the HA/β-TCP composites is about 400-500 μm. The relative density of the porous HA/β-TCP composite increased with decreasing SH content. The porous HA/β-TCP composite fabricated with 30%SH exhibited an elastic modulus similar to that of cortical bone; however, the compression strength of this composite is higher than that of cortical bone.