Corrosion behavior and mechanism of laser directed energy deposited Cu Nb alloys under arc discharge

The refractory metal Nb can improve the ablation resistance of copper alloy. In this study, the microstructures, composition, physical properties and arc corrosion mechanism of copper substrate and Cu Nb deposited alloys with different Ti addition after arc discharge test in air were studied. Results show that in addition to the formation of arc ablation pit, there is a melting and recrystallization area where the grains are significantly refined. The depth and volume of the arc ablation pit can be attributed to the vaporization of Cu and the splashing of the liquid. The arc ablation of the copper substrate is dominated by the vaporization of Cu, but for the Cu Nb and Cu-Nb-Ti deposited alloys is melt-dominated. Finally, the depth and volume of the arc ablation pit of copper substrate is the largest with the value of 412.37 μm and 5.44 mm 3 , respectively. Based on the depth and volume of the arc ablation pit, the Cu Nb and Cu-Nb-Ti deposited alloy exhibit better ablation resistance compared with the copper substrate. • The Corrosion behavior and mechanism of Cu Nb deposited alloys were studied. • The Cu Nb deposited alloys exhibit better ablation resistance. • The Ti element will slightly degrade the ablation resistance.