Eventos Anais de eventos
COBEM 2019
25th International Congress of Mechanical Engineering
MICROSTRUCTURE, MECHANICAL PROPERTIES AND CORROSION SUSCEPTIBILITY OF Ti-35Nb-4Sn ALLOY PROCESSED BY LASER MELTING
Submission Author:
Juliane Ribeiro da Cruz Alves , SP
Co-Authors:
Juliane Ribeiro da Cruz Alves, Milton Sergio Fernandes de Lima, Rodnei Bertazzoli
Presenter: Juliane Ribeiro da Cruz Alves
doi://10.26678/ABCM.COBEM2019.COB2019-2410
Abstract
The effect of laser melting on the corrosion susceptibility and mechanical properties of Ti-35Nb-4Sn (mass%) alloy is investigated across the melted track profile. Microstructure is assessed by optical and scanning electron microscopy, and by energy dispersive x-ray spectroscopy. Mechanical properties are determined by Vickers microhardness measurements and by nanoindentation analysis. Corrosion susceptibility is investigated by linear potential scan voltammetry. In comparison to the cold-rolled microstructure of base metal, plastic energy absorption and pitting corrosion resistance were improved in heat affected zone (HAZ) due to recrystallization and eventual reduction of active sites for pit nucleation. In fusion zone, however, passivation was compromised by the formation of dendritic microstructure with Sn enriched interdendritic region, where preferential pitting corrosion occurred. Fusion zone was the most anodic region and presented a corrosion potential difference of 35mV, in comparison to the adjacent and most cathodic HAZ. Local increase in elastic modulus and microhardness of fusion zone shows that laser melting is a viable processing route for the manufacturing of biomaterials with graded properties.
Keywords
β-phase Ti-35Nb-4Sn alloy, Laser welding, Low Young’s modulus
