Fatigue behavior and physical characterization of surface-modified Ti-6Al-4V ELI alloy by micro-arc oxidation

Fernanda Potomati,Claudemiro Bolfarini,Laís Tereza Duarte,Nelson Guedes de Alcântara,Enrico José Giordani

doi:10.1590/s1516-14392012005000012

Fernanda Potomati, Claudemiro Bolfarini + Show 3 more

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https://doi.org/10.1590/s1516-14392012005000012

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Journal: Materials Research	Publication Date: Feb 14, 2012
Citations: 21	License type: cc-by

Affiliation: Universidade Federal de São Carlos

Abstract

Anodizing has proven an effective method for preparing bioactive titanium and has been the subject of many studies regarding the performance and biological characterization of the layers obtained. However, the fatigue behavior of titanium alloys, after undergoing this process is still poorly studied. This study aims to investigate the influence of MAO (Micro-Arc Oxidation) process on the fatigue properties of titanium alloy Ti-6Al-4V. Therefore axial fatigue tests were performed to obtain SxN curves, of specimens in polished and anodized (MAO processed, phosphate salt solution, potential of 290 V) conditions. Roughness measurements, SEM, Raman spectra and X-ray photoelectron spectroscopy (XPS) analyses were used to characterize the features of the modified surface. SEM was also used to analyze the fatigue fractures of the tested specimens. The MAO process, with the parameters used in this investigation, had no influence on the fatigue behavior of the Ti-6Al-4V alloy, when compared to specimens without surface modification.

Highlights

Anodized surfaces result in better bone response, with better biomechanical results, when compared to machined surfaces[1]
The micro-arc oxidation (MAO) process is typically characterized by the phenomenon of electrical discharge on the anode in aqueous solution
Before the voltage oscillations begin, the specimens are already passivated by an oxide film that is basically a non-porous, compact, and uniform barrier-type film[22,23]

Summary

Introduction

Anodized surfaces result in better bone response, with better biomechanical results, when compared to machined surfaces[1]. Among the various processes of electrochemical oxidation, micro-arc oxidation (MAO), known as anodic oxidation or plasma spark electrolytic oxidation (PEO), has been the subject of several studies of surface modification of titanium and its alloys for biomedical use[8,9,11,12,13,14,15]. It is an anodic oxidation technique for deposition of ceramic layers on the surface of metals such as Al, Ti, Mg, Ta,Zn and their alloys[3]. The discharge channels have temperatures above 10.000 K and a local pressure of several hundred bars[3]

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