Study Of The Preparation Of Bioactive Layer On The Ti-based Bulk Metallic Glasses

Ti-based bulk metallic glasses (BMGs) have been studied extensively as a new type of biomaterials owing to their excellent mechanical properties, low Young’s modulus and high elastic limit. Ti4oZr10Cu34Pd16alloys system, without any toxic elements, exhibits good glass-forming ability. However, the biocompatibility of Ti-based bulk glassy alloy is essential when it is used as the candidate for implant.In this work, a Surface modification method is developed to improve the biocompatibility of Ti-based bulk glassy. A bioavtive surface was formed by Acid-alkali pretreatment and a layer of calcium phosphate was prepared n the surface of Ti40Zr10Cu36Pd14BMG samples. The scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron (XPS) and Micro-Raman Spectroscopy were employed to investigate the morphology, component and microstructure of the composite coatings.The result shows that:a bioactive layer was formed on the surface ofthe sample dipped in HNO3 aqueous solution and boiled in 1 M NaOH aqueous solution. After immersion in 1.5×simulated body fluid (SBF) for 14 d, a coating mainly consist of hydroxyapatite (HA) was deposited on the surface pre-treated samples. The Ca/P of the apatite coating was 1.62, and increased by immersion time. The formation of the apatite coating can be divided in two subsequent steps:(1) uniform thin layer first generated and (2) rough layer composed of bigger globules.In addition, a TiO2 coating in anatase type was prepared by sol-gel technique, and in SBF immersion, the TiO2 coatings can induce deposition of calcium phosphate coating composed of hydroxyapatite.