Hydroxyapatite/Titanium Composite Coating for Biomedical Applications

Cold Spray;Plasma Spray;Hydroxyapatite/Ti Composite Coating;Electrochemical Corrosion Behavior Test;Biomedical Application;Electrochemical Impedance Spectroscopy (EIS);Biomedical Applications;Automotive Systems Engineering;Automotive Systems Engineering

Zhou, XuanGuduru, Ramesh ;

University of Michigan

关键词: Cold Spray;    Plasma Spray;    Hydroxyapatite/Ti Composite Coating;    Electrochemical Corrosion Behavior Test;    Biomedical Application;    Electrochemical Impedance Spectroscopy (EIS);    Biomedical Applications;    Automotive Systems Engineering;    Automotive Systems Engineering;   

Others  :  https://deepblue.lib.umich.edu/bitstream/handle/2027.42/94569/Xuan_Zhou_Dissertation.pdf?sequence=1&isAllowed=y

瑞士|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

Hydroxyapatite, (HAP), a calcium phosphate bioceramic material, has been widely used in both dentistry and orthopaedics due to its biocompatibility and osteoconductivity. However, its poor bulk mechanical properties have limited its use as load bearing material. An effective approach to solve this problem is to form a composite coating of HAP and Titanium, in which titanium will be the matrix and HAP will act as reinforcement.In this research, two novel approaches, namely cold gas dynamic spraying (CGDS) and argon atmosphere plasma spraying (AAPS), were applied to manufacture HAP/Ti composite coatings. The aim was to produce thick and dense deposits and investigate the mechanical, electrochemical and incubation behavior of such biocomposites as potential load bearing materials for biomedical applications. The complex nature of the manufacturing processes and the characteristics of these materials make this a challenging study in terms of coating manufacturing and property evaluation. For cold sprayed HAP/Ti composite coatings, it was found that the phase composition of the HAP in the deposits was identical to that of the precursor powder and the bond strength of the deposit was comparable/better to that of the plasma sprayed 100% HAP typically used in industry. A relatively higher corrosion current of HAP/Ti composite than that of pure Ti coating in simulated body fluid indicated a good bioactivity for composite coating, which was also verified by the formation of apatite layer on the surface of composite coating in in-vitro testing. The cold sprayed HAP/Ti composite is expected to be a promising load-bearing implant material for biomedical applications.For AAPS-deposited HAP/Ti composite coatings, results demonstrated that dense composite coatings with a typical morphology of HAP homogenously distributed in Ti matrix was obtained and the decomposition of HAP during plasma spraying process was avoided. The bond strength was significantly higher than that of 100% HAP or Ti reinforced cold sprayed HAP coatings and the frictional property was comparable to the Ti substrate. A relatively higher corrosion current of HAP/Ti composite than that of pure Ti coating indicated a good bioactivity, which was also verified by the formation of apatite layer in in-vitro testing. Therefore, AAPS deposited HAP/Ti composites are also potential material for load bearing implant materials. However, oxidation free HAP/Ti coatings could only be achieved under argon environment which makes the process expensive. In contrast, the cold spray technique does not require any protective environment; thus can be an inexpensive approach.