Abstract: The ultrasonic rolling process can strengthen the compressor blades and extend their working life,but due to the limited structure of the blade root,conventional ultrasonic rolling equipments are difficult to process the restricted space at the root.In order to make the ultrasonic rolling equipment better adapt to such spaces,after improving the structure of the ultrasonic rolling tool head,the influence of tool head size was concerned in the optimization design of the horn size.With the joint simulation of Abaqus and Matlab software,the horn size with stable longitudinal vibration frequency and amplification factor was obtained when installing the tool head,and the overall design of the ultrasonic rolling equipment was improved.By processing flat test specimens,the influence of the equipment on surface integrity under different processing parameters was analyzed.Based on this,the optimal processing parameters were selected and fatigue performance experiments were conducted on bending fatigue vibration test specimens.The fatigue life of the processed test specimens was improved.The processing experiment was conducted in the confined space at the root of the blade-type structural component,and the surface integrity of the processed sample piece was significantly improved.The successful strengthening of confined spaces proves that the ultrasonic rolling equipment with wheeled cutting heads can be applied to parts with narrow confined spaces such as the root of compressor blades,and is expected to further improve the surface integrity and fatigue life of some components with complex features and structures.

Key words: ultrasonic rolling, horn design, confined space, surface integrity