Mechanical and Tribological Properties of Ca/P-Doped Titanium Dioxide Layer Produced by Plasma Electrolytic Oxidation: Effects of Applied Voltage and Heat Treatment

AbstractPlasma Electrolytic Oxidation (PEO) is a technique that produces a hard oxide layer on the titanium surface where its properties can be tailored by changing the process parameters or by a posterior heat treatment. In this work, a TiO2 layer with different crystallinity was produced by PEO with different applied voltages (250 to 400 V) and post heat treatment at 600 °C. Our aim was to evaluate the influence of the PEO voltage and heat treatment on the mechanical and tribological properties of anodized Ti. There is an increase in pore size, oxide thickness and Ca/P ratio for the oxide layer with the applied voltage during the PEO process. XRD results indicated an increase in the crystalline rutile phase in the oxide layer with voltage and heat treatment. Nanoindentation shows an increase in the oxide hardness and elastic modulus with increased voltage and heat treatment; leading to an improvement in the wear resistance.