The aim of this grant is to investigate a novel multiple-layer laser coating process to form functionally gradient bioceramic coatings on Ti6Al4V metal substrates. Most of the current commercial bioactive ceramic coatings 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 project 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. The intellectual merits of the project are: (a) The fundamental mechanism of multilayer functional coatings of bioceramic materials will be investigated for the first time; (b) Advancing laser materials processing technique: An unique way to form low temperature HAp coating will be realized through laser surface engineering. (c) This coating technique offers uniqueness over the existing coating techniques: Strong HAp/Ti/Metal substrate interface can be obtained through gradient porosity and HAp density.
The successful completion of this grant will significantly improve the lifetime of bioceramic coatings. This project will also increase the presence of nontraditional manufacturing (NTM) techniques in manufacturing education through the following ways: 1) creating an interdisciplinary environment that integrates nontraditional manufacturing research and teaching, (2) providing multidisciplinary research opportunity for students, and (3) recruiting good students and retain them in science and engineering through outreach activities for undergraduate students.
