Microstructures, mechanical properties and corrosion resistances of FCC CoCrFeNiTi high-entropy alloys prepared by pre-alloyed powder mixing and vacuum laser-directed energy deposition

• FCC structure is maintained in CoCrFeNiTi HEAs up to x = 0.3, with grain refinement and increased precipitate content as Ti increases. • CoCrFeNiTi0.3 offers the best tensile properties: TYS of 604 MPa, UTS of 882 MPa, and elongation of 13.5%, corresponding to 124% and 83% improvements over the Ti-free alloy. • CoCrFeNiTi0.2 exhibits superior corrosion resistance, with high passive film resistance and charge transfer resistance values. • Ti addition improves corrosion resistance by increasing Cr and Ti concentrations in the passive film, forming a more protective layer.