Ti-6A1-4V-_(xx)Zr합금의 시효처리에 따른 미세조직 변화와 내식성에 미치는 Zr 첨가 효과

Abstract

The use of titanium and its alloy as biomaterial is increasing due to their low modulus, superior biocompatibility and enhanced corrosion resistance when compared to conventional stainless steel and cobalt-based alloys. The aim of this paper is to study the effect of zirconium addition on corrosion resistance and phase formation in the specimen of the manufactured Ti-6Al-4V-_(xx)Zr alloys. We designed the Ti-6Al-4V-_(xx)Zr alloys with zirconium contents ranging from 10 to 30 wt% In steps of 10 wt%. The alloys were arc-melted an homogenized at 650 ℃ for 12 hr. Heat treatments constituted a higher temperature solution treatment in the β phase field(1030 ℃) or in the α+β phase field(800 ℃) followed by an aging treatment. The samples for optical metallography, scanning electron microscopy were prepared using standard techniques and etched with Kroll's reagent. X-ray diffraction(XRD) analysis for specimens were performed using a philips 3121 diffractomenter. Effect of alloy composition on the corrosion resistance was studied by anodic polarization test. From the results of anodic polarization behavior in Ti-6Al-4V-_(xx)Zr alloys, it was found that the corrosion resistance was increased with increasing Zr content.