title: Biphasic calcium phosphate coating on cobalt-base surgical alloy during investment casting.
abstract: The biphasic calcium phosphate (BCP) yields higher bioactivity and efficiency than the Hydroxyapatite (HA) alone. The HA/β-TCP ratio significantly affects BCP bioactivity as well as the extent of BCP resorption. In this study, the BCP coating on ASTM F-75 cobalt base alloy during the investment casting process was investigated. For this purpose, molten metal was poured at 1,470°C into previously coated investment molds preheated to 750, 850, 950, 1,050°C in order to investigate the effect of mold preheating temperatures on coating phase transformations. For in vitro evaluation, samples were immersed in the simulated body fluid (SBF) at 37°C for 4 weeks and characterized by XRD, SEM, EDS, and optical microscopy. The weight percentages of HA and β-TCP of the specimens were calculated to find that the HA/β-TCP ratio significantly depended on the mold preheating temperature as it caused changes in the dissolution behavior of BCP coating and the bone-like apatite precipitation on coating during in vitro evaluation.
authors: Department of Materials Engineering, Isfahan University of Technology, 8415683111 Isfahan, Iran. h_minouie@yahoo.com
authors: H
authors: H
authors: Minouei
authors: M
authors: M
authors: Meratian
authors: M H
authors: MH
authors: Fathi
authors: H
authors: H
authors: Ghazvinizadeh
mesh_terms: D000497:Alloys; D001672:Biocompatible Materials / Q000737:chemistry*; D003035:Cobalt / Q000737:chemistry*; D006882:Hydroxyapatites / Q000737:chemistry*; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D013499:Surface Properties
chemical_list: D000497:Alloys; D001672:Biocompatible Materials; D006882:Hydroxyapatites; C074950:hydroxyapatite-beta tricalcium phosphate; D003035:Cobalt