Corrosion Susceptibility and Functionally Graded Properties of Ti-35Nb-4Sn Alloy Processed by Laser Remelting

Author(s)

Juliane Ribeiro da Cruz ^[1] ; Milton Sérgio Fernandes de Lima ^[2] ; Rodnei Bertazzoli ^[3]

Affiliation

^[1] Instituto Tecnologico de Aeronautica. Departamento de Engenharia Mecânica - Brasil

^[2] Instituto de Estudos Avancados. Divisão Fotônica - Brasil

^[3] Universidade Estadual de Campinas. Faculdade de Engenharia Mecânica - Brasil

• Document type: Journal article
• Source: MATERIALS RESEARCH-IBERO-AMERICAN JOURNAL OF MATERIALS; v. 23, n. 1 2020-05-11.

Abstract

The effect of laser remelting on the corrosion susceptibility and mechanical properties of Ti-35Nb-4Sn (mass%) alloy is investigated across the remelted track profile. In comparison to the cold-rolled microstructure of base metal, recrystallization of heat affected zone (HAZ) improved plastic energy absorption and pitting corrosion resistance, by the 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 35 mV, in comparison to the adjacent and most cathodic HAZ. Electrochemical impedance analysis showed that spontaneous passivation was most effective in base metal, that developed a thicker and more compact passive film. Local increase in elastic modulus and microhardness of fusion zone shows that laser remelting is a viable processing route for the manufacturing of biomaterials with functionally graded properties. (AU)

• FAPESP's process: 16/10637-4 - Development of a corrosion microprobe for monitoring of the effects of laser micro welding on the properties of Ti-Nb-xSn and Ni-Ti alloys
• Grantee: Rodnei Bertazzoli
• Support Opportunities: Regular Research Grants