Laser Engineered Multilayer Bioactive Coatings with Hydroxyapatite Nano-Powders

Washington State University, Pullman WA

Investigators

Abstract

The aim of this research program is to investigate a novel multiple-layer laser coating process to form functionally gradient bioceramic coatings on Ti6Al4V metal substrates. Application of bioactive ceramic coatings, such as Hydroxyapatite (HAp), is common in load bearing metal implants to improve cell-materials interaction and reduce healing time. However, most of the commercial coating processes present a sharp coating/substrate interface, which is always a potential source of weakness because severe stresses can build up due to the mismatch of mechanical properties and thermal expansion coefficients between the implant and coating material. This program seeks to overcome these problems with a laser engineered multilayer bioactive coating with HAp nano-powders in which a progressive change in both microstructure and properties over the interface will be attained. More specifically, the aims of this project are: (a) synthesis of nano-scale hydroxyapatite particles with tailored size and morphology using micelle and reverse micelle template systems; (b) processing of porous single and multiple-layer HAp/Ti coatings on Ti6Al4V substrate by pulsed laser surface engineering; and (c) characterization of physical, mechanical and biological properties. Process parameters will be optimized to achieve good bonding strength while maintaining phase purity and biocompatibility. The successful completion of this work will significantly improve the lifetime of bioceramic coatings. This work will increase the presence of nontraditional manufacturing (NTM) techniques in manufacturing education by establishing a strong research program involving laser manufacturing. Students will be recruited and encouraged to participate in this project through outreach activities for high school students and under-represented minorities.