Microstructure design to improve the corrosion and cavitation corrosion resistance of a nickel-aluminum

Microstructure evolution of the nickel-aluminum bronze alloy was studied by heat treatment, including annealing, normalizing, quenching and aging. The microstructure was refined and homogenized after quenching or quenching/aging at 450 degrees C, which can eliminate selective phase corrosion effectively. Compared with the current production process, static corrosion rate reduced about 50%, due to the rapid formation of a protective film. In addition, cavitation corrosion rate reduced by a factor of 4.9 and 7.9 for the quenched and quenched/aged at 450 degrees C samples, respectively. This can be attributed to the improved hardness and weakened synergy between corrosion and mechanical attack.