Physical properties evolution of β-tricalcium phosphate/hydroxyapatite heterostructures in relation to the bilayer number

Abstract

Tribo-mechanical properties for the heterostructures based on β-tricalcium phosphate (β- TCP) (Ca3(PO4)2) and hydroxyapatite (HA) (Ca5(PO4)3(OH)) as a function of the bilayers number (n = 1, 10, 30 and 50) were deposited on metallic AISI 302 steel substrates. In this sense, the β-TCP layer was deposited on the substrate surface, and the HA layer was deposited on the multilayer system surface (Steel [β-TCP/HA]n).The results obtained shows a reduction of 46% in roughness and a 16% in grain size when comparing the coating with 50 bilayers with the coating with 1 bilayer. Subsequently, the coating with 50 bilayers showed an increase of 108% in the hardness compared to the coating with 1 bilayer and the tribological properties showed a reduction in the friction coefficient of 32% of the coating with 50 bilayers with the coating with 1 bilayer. The results obtained in this research evidenced that the coating with 50 bilayers presented the best set of surfaces, mechanical and tribological properties. In this sense, this heterostructure coating deposited with n = 50 bilayers is the best option to be incorporated on biomedical devices, in order to confer higher wear resistance in the biomedical equipments.