Microstructure and properties of porous titanium prepared by spark plasma sintering

Abstract

Porous titanium samples with a porosity of 1.34~15.54% were prepared by a spark plasma sintering (SPS) process at sintering temperatures of 800◦C, 850◦C and 900◦C, and a sintering pressure of 10 MPa. The microstructures and fracture morphology of the samples were investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses. The compressive strength and elastic modulus were likewise measured. The results showed that no new phase occurred after the samples were sintered, and the main phases were α phase of hcp structure. The porosity of the samples decreased significantly with the increase of sintering temperature. At 800◦C, the sample phase was dominated by equiaxed α. There were more irregular coarse pores in the samples. At 850◦C, the microstructure was mainly zigzag α, and the pores were finely and relatively uniform in distribution. At 900◦C, the sample’s structure transformed into a dense sheet-like α. The sample’s densities increased and the pores disappeared. The room temperature compression test showed that the porous titanium sintered by SPS had excellent compressive strength. The yield strength, compressive strength, compressive strain and elastic modulus were 81.85~122.36 MPa, 161.65~498.86 MPa, 36.75~59.97% and 2.79~4.22 GPa, respectively.