On cavitation erosion behavior of friction stir processed surface of cast nickel aluminium bronze

- Friction stir processing reduces grain size of cast NAB alloy.
- FSP increases tensile strength and resistance to cavitation and corrosion.
- Inter granular corrosion attack takes place of NAB alloy both in as-cast and FSPed condition.
- The cavitation behavior is governed by strengthening due to grain refinement and work hardening of the FSPed surfaces of the NAB alloy.

The cavitation erosion of friction stir processed (FSPed) cast nickel aluminium bronze has been investigated. The friction stir processing (FSP) was performed for different set of process parameter using design of experiment (DOE) approach. The effect of process parameters on the cavitation erosion was studied. The result suggested that increasing tool rotation (R) and tool shoulder (D) decreases the mass loss due to cavitation (mc). However, increasing the tool travel speed (S) increases the mass loss due to cavitation (mc). The properties of FSPed surface, including ultimate strength and corrosion resistance were also evaluated. These properties were correlated with the mass loss due to cavitation (mc). A good correlation of FSPed surface grain size and hardening capacity with mass loss due to cavitation (mc) was obtained. The scanning electron microscopy (SEM) of the eroded surface, subsurface and corroded surface was performed. Cavitation behavior of FSPed surface has been discussed using mechanical properties and microstructure.