Session BB3.6

11:15 AM BB3.6
SYNTHESIS AND CHARACTERIZATION OF NANOCRYSTALLINE COATINGS BY HIGH VELOCITY OXY-FUEL SPRAY PROCESSING FOR BIOMEDICAL APPLICATIONS. Maggy L. Lau, Hong G. Jiang, Enrique J. Lavernia, Department of Chemical Engineering and Materials Science, University of California-Irvine, Irvine, CA; Carlos J. Lavernia, Department of Orthopedics and Biomedical Engineering, University of Miami, School of Medicine, Miami, FL.

In recent years, much research has been focused on various methods to produce coated implants for numerous biomedical applications. Thermal spray processing provides a potential means to rapidly deposit a coating onto an implant which facilitates the bonding between the implant surface and bone tissues. The present paper describes the synthesis and characterization of nanocrystalline coatings which may improve the quality of hip implants in the future. The feedstock powders were prepared by mechanical milling in which micron-sized powders were milled in a methanol environment to produce flake-shaped agglomerates with the average grain size of less than 100 nm. The powders were then introduced into the high velocity oxy-fuel (HVOF) process to produce nanocrystalline coatings. X-ray diffraction analysis was used for phase identification and to determine the average grain size of the milled powders as well as the coatings. Scanning electron microscopy and transmission electron microscopy were used to analyze the particle morphology as well as the microstructure of the coatings. In addition, coating properties of various materials were characterized by corrosion and hardness measurements. The results are compared to those of the micron-sized coatings.