SUMMARY

Co-flow cavitation peening is a surface treatment process used to generate beneficial compressive residual stresses while being environmentally sustainable and amenable to
automation. Compressive residual stresses generated by the collapse of the cavitation cloud at the workpiece surface result in enhanced fatigue and wear performance. However, an increase in cavitation intensity is needed to reduce the processing time for practical applications and to enhance process capabilities for a wide range of materials. Scaling of the nozzles to enhance cavitation intensity requires increase in pump capacity and can be capital intensive. An alternate approach is to investigate new nozzle designs to enhance the cavitation intensity. One of the most important aspects of overall design in co-flow nozzles is the high-pressure inner jet nozzle, which can be engineered to achieve greater cavitation intensity. Another way of increasing cavitation intensity is through the addition of cavitation promoting soluble additives to the cavitation media, which has not been explored in cavitation peening. The proposed seeks to address the following research questions pertinent to cavitation intensity enhancement in water cavitation peening: 1)
What inner jet nozzle geometry modifications and associated flow mechanisms can enhance cavitation intensity in co-flow water cavitation peening? 2) Can cavitation intensity in water cavitation peening be enhanced by the introduction of suitable additives to the cavitation media?