Microstructural characteristics with process-microstructure-property relations during high-frequency ultrasonic vibration-assisted cutting of metallic material

Microstructural characteristics of chips and machined surfaces are influenced by the multiphysics fields distribution. This study investigates the multiphysics-induced microstructural deformation behaviors of CuZn37 metallic alloy during high-frequency ultrasonic vibration-assisted cutting (HFUVAC) and conventional cutting (CC). One the one hand, the multiphysics field distribution was established to clarify the chip formation of cutting characteristics and transient deformation process. The multiphysics field distribution of HFUVAC exhibited periodic changes due to tool intermittent movement, resulting in reduced cutting temperature and force. This intermittent movement also enhanced the sharpening shear effect due to instantaneous impact stress, transitioning from fragmented quasi-shear strain to continual multiple-shear strain during chip formation. One the other hand, the microstructural changes were examined to explain material removal mechanisms. The microstructure of CC demonstrated grain refinement and dislocation slip induced by friction and significant shear deformation. The microstructure of HFUVAC revealed the formations of dynamic recrystallization, twinning structures, and stacking faults, which were associated with enhanced plastic activity and limited slipping due to high-frequency impacts. The work reveals the response of the workpiece microstructure under the composite effects of high-frequency impacts and cutting process, which provides theoretical basis for the microstructure modification design through cutting technology.