Effect of laser surface re-melting on the microstructure and properties of Zr alloy

•The surface hardness and corrosion resistance of the Zr-5Ti alloy are improved by LSR process.•Grain refinement reduces the pitting corrosion sensitivity of the alloy.•The oxide content of passivation films of Zr-5Ti increases after LSR, which increases the corrosion resistance of the alloy. The effects of laser surface re-melting (LSR) on the mechanical and corrosion properties of Zr-5Ti are investigated. After LSR, the microstructure of the alloy-surface has a finer phase-structure and higher density of grain boundaries. Furthermore, the surface hardness of the Zr-5Ti alloy improves significantly due to grain refinement. With increasing distance from the surface, the hardness decreases gradually because the laths coarsen gradually. Corrosion resistance after LSR also clearly improves due to grain refinement, which also reduces the pitting corrosion sensitivity of the alloy. The generated passivation film of the laser-treated alloy and substrate is also analyzed in this paper using X-photoelectron spectroscopy.