Spark Plasma Sintering of PSZ-Ti Composites Using Ceramic-Coated Ti Powder to Suppress Sintering Reactions

This study aims to fabricate partially stabilized zirconia (PSZ)-titanium (Ti) composites to produce implants having ceramic and metallic characteristics. To fabricate such materials via powder metallurgy, sintering reactions must be suppressed. In this study, ceramic-coated Ti powder was used as a starting material to suppress Ti oxide formation. Yttria was coated on Ti powder using the sol-gel technique, the Ti powder was mixed with PSZ powder, and the mixed powders were sintered. From the results of optical microscopy and XRD analysis, dense PSZ-Ti composites containing the yttria phase were successfully fabricated without any reaction products. Hardness and bend tests revealed that the hardness and elastic modulus of the composites increased with the increase of PSZ content and agreed with the predicted values based on the rule of mixtures. Bend tests also revealed that the strength did not improve, as the brittle yttria phase preferentially fractured in the composites subjected to bending.