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).

The effect of heat treatment on the microstructure and mechanical properties of cast Ti-6%Al-4%V alloy was investigated. Heat treatment of cast Ti-6Al-4V alloy was conducted by solution treatment at 950 oC for 30 min; this was followed by water quenching and then aging at 550 oC for 1 to 1440 min. The highest hardness of the heat-treated specimens was obtained by solution treatment and subsequent aging for 5 min due to precipitates of fine α that formed from retained β phase. The tensile strength of this alloy increased without dramatic decrease of the ductility due to microstructural refinement resulting from the decomposition of α' martensite into fine α and β phases, and also due to the fine α phase formed from the retained β phase by aging treatment for 5 min. In addition, this strengthening might be caused by the transformation induced plasticity (TRIP) effect, which is a strain-induced martensite transformation from the retained β phase during deformation, and which occurs even after aging treatment at 550 oC for 5 min.

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.

Hot rolling of Mg-6Zn-0.6Zr-0.4Ag-0.2Ca-(0, 8 wt%)Li powder was conducted at the temperature of 300 oC by putting the powder into the Cu pipe. The microstructure and mechanical properties of the samples were observed. Mg-6Zn- 0.6Zr-0.4Ag-0.2Ca without Li element was consisted of α phase and precipitates. The microstructure of the 8 wt%Li containing alloy consisted of two phases (α-Mg phase and β-Li phase). In addition, Mg2Zn3Li was formed in 8%Li added Mg-6Zn-0.6Zr- 0.4Ag-0.2Ca alloy. By addition of the Li element, the non-basal planes were expanded to the rolling direction, which was different from the based Mg alloy without Li. The tensile strength was gradually decreased from 357.1 MPa to 264 MPa with increasing Li addition from 0% to 8%Li. However, the elongation of the alloys was remarkably increased from 10 % to 21% by addition of the Li element to 8%. It is clearly considered that the non-basal texture and β phase contribute to the increase of elongation and formability.

The phase Ti-Nb-Sn-HA bio materials were successfully fabricated by high energy mechanical milling and pulse current activated sintering (PCAS). Ti-6Al-4V ELI alloy has been widely used as biomaterial. But the Al has been inducing Alzheimer disease and V is classified as toxic element. In this study, ultra fine sized Ti-Nb-Sn-HA powder was produced by high energy mechanical milling machine. The phase Ti-Nb-Sn-HA powders were obtained after 12hr milling from phase. And ultra fine grain sized Ti-Nb-Sn-HA composites could be fabricated using PCAS without grain growth. After sintering, the microstructures and phase-transformation of Ti-Nb-Sn-HA biomaterials were analyzed by scanning electron microscope (SEM) and X-ray diffraction (XRD). The relative density was obtained by Archimedes principle and the hardness was measured by Vickers hardness tester. The -Ti phase was obtained after 12h milling. As result of hardness and relative density, 12h milled Ti-Nb-Sn-HA composite has the highest values.