Microstructure and corrosion behavior of the annealed Zr–40Ti–5Al–4V alloys

The microstructure and corrosion behavior of novel Zr–40Ti–5Al–4V alloys with different annealing temperatures were investigated. The specimens annealed from 500 to 800 °C were composed of α and β phase. Obtained results revealed that the mean thickness of α phase and the volume fraction of β phase increased with the increasing annealing temperature below 700 °C but decreased when annealed at 800 °C. Potentiodynamic polarization analysis indicated that all of the alloys present similar corrosion behavior in 3.5% NaCl and 5% HCl solution. A rapid increase in the current densities was observed for all the alloys in both solutions, which could be related to passivity breakdown caused by pitting corrosion. Uniformly distributed pits were also found on the surfaces of the annealed alloys during the immersion test. Annealing heat treatment modified the microstructures of the alloys but had little influence on their corrosion behavior. [Display omitted] •Structure and corrosion behavior of novel Zr–40Ti–5Al–4V alloy was investigated.•Thickness of α phase and β phase content varied with annealing temperature.•Pitting corrosion was observed in both electrochemical and immersion tests.•Heat treatment had little influence on the corrosion behavior of the alloys.