Effect of laser surface melting on microstructure evolution and cavitation behavior of nickel aluminum bronze
(State Key Laboratory of Material Processing and Die and Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China)
Abstract: The laser surface melting was employed on the nickel aluminum bronze to augment the cavitation performance. To investigate the effect of laser treatment, the microstructure was characterized by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. And the cavitation behavior was tested on an ultrasonic vibratory machine. The results show that the optimal process parameter with laser power of 3 kW and scanning speed of 10 mm/s contributes to the increased corrosion resistance and reduced cavitation mass loss, compared with the cast sample, respectively. The enhancement of the cavitation resistance is dominated by the synergistic mechanism of grain refinement strengthening, dislocation strengthening, and precipitate strengthening, with the homogeneous structure eliminating selective corrosion.
Key words: nickel aluminum bronze; laser surface melting; precipitates; dislocation