Analytical modeling of surface generation in ultrasonic ball burnishing including effects of indentation pile-up/sink-in and chipping fracture

In mechanical based machining processes, the surface topography is generated through series of hierarchical pattern. Plastic deformation as result of contact and kinematic of motion are two main factors which determine evolution of surface generation. To basically optimize the surface quality, accurate predictive model of surface generation and constraints are required. In the present work, analytical models of dimple formation and hierarchical surface generation in ultrasonic assisted ball burnishing process are proposed. Pile-up and sink-in as two phenomena of indentation during both of loading and unloading phases were taken into the developed models. Considering interaction of indentation profile and kinematic of motion, three-dimensional surface topography and surface roughness are also analytically predicted. A criterion for surface failure is defined to perform process without any erosion. Confirmation of results have been made by series of single trace and multi-traces burnishing experiments on AA6061-T6 and AISI 1045. The results of indention profile, surface topography, roughness and failure criterion which were derived from predictive models were completely consistent with confirmatory experiments.