Corrosion Resistance of Titanium-Platinum Alloy Prepared by Spark Plasma Sintering

The microstructure and corrosion resistance of Ti–Pt alloys prepared from Ti and Pt powders using spark plasma sintering (SPS) were investigated. The microstructure of SPS specimens was observed by scanning electron microscopy and X-ray diffraction analysis. The Pt phases were found to be dispersed throughout the Ti matrix, and some Ti–Pt intermetallic compounds formed around the Pt phases were observed. The corrosion behavior of SPS specimens was evaluated by potentiostatic polarization measurement in a 5% (by mass) HCl solution. The Pt and Ti3Pt phases appear to be responsible for the high corrosion resistance, and cathode reaction on the Pt phases maintaining Ti in the passive state. Therefore, the Ti matrix becomes appreciably more passive than arc-melted Ti–Pt alloys. Thus, the present method allows improvement in corrosion resistance by adding a very low percentage (by mass) of Pt.