Fabrication of compositionally and structurally graded Ti-TiO2 structures using laser engineered net shaping (LENS)

Novel structures with functional gradation in composition and structure were successfully made in Ti-TiO2 combination using laser engineered net shaping. The addition of fully dense, compositionally graded TiO2 ceramic on porous Ti significantly increased the surface wettability and hardness. The graded structures with varying concentrations of TiO2 on the top surface were found to be non-toxic and biocompatible. In addition, the higher wettability of surfaces with TiO2 can enhance their ability to form chemisorbed lubricating films, which can potentially lower the friction coefficient against ultrahigh molecular weight polyethylene liner, thus reducing its wear rate. These unitized structures with open porosity on one side and hard, low friction surface on the other side can eliminate the need for multiple parts with different compositions for load-bearing implants such as total hip prostheses. (c) 2009 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.