Erosion characteristics of surface hardened Ni–Al bronze

Abstract

Surface hardness characteristics and erosion resistance of Ni–Al bronze produced by three kinds of quenching have been determined to assess their potential as surface treatments for marine propellers. Flame, high frequency, and laser processing were employed as the surface hardening treatments. Microstructures and distributions of alloying elements were examined using microscopy, computer image analysis, and EP MA. Jominy and ultrasonic erosion tests were also conducted to evaluate the depth of surface hardening andresistance to propeller cavitation erosion. The experiments revealed that Ni–Al bronze has quenching characteristics closely related to those of steel and that bronze surface hardened by flame quenching is about 1·5 times harder than as cast. It was also found that lame quenching is the most suitable technique for surface treatment of propellers.