Microstructure and properties of Ti60 alloy by laser solid forming and ultrasonic impact hybrid manufacturing

The hybrid manufacturing of laser solid forming (LSF) and ultrasonic impact treatment (UIT) was used to improve the structure and properties of Ti60 alloy by strengthening the surface layer-by-layer. The microstructure, mechanical properties, and burn resistance of LSFed Ti60 samples before and after UIT by SEM, TEM, and XRD were analyzed and compared. The results showed that the grains of LSFed Ti60 alloy were refined and metallurgical defects were reduced after the UIT process. Meanwhile, the deposited layer was severely deformed after UIT and nanocrystals were formed on the surface. In addition, the microhardness of the deposition layer surface increased and the residual stress changed from tensile stress to compressive stress. The area of the ablation hole was reduced by 21% and the proportions of Mo, Nb, and Zr elements increased. In summary, hybrid manufacturing of LSF and UIT can improve the microstructure and properties of LSFed Ti60 samples.