Development of a vibration-assisted compression texturing process with predictable micro-dimple geometry

A vibration-assisted compression texturing process was developed for deterministic generation of micro-dimple arrays on magnesium–lithium alloy surfaces through localized plastic deformation without material removal. A piezo-actuated compression device was designed and integrated into a CNC milling machine to enable controllable chipless surface texturing. To support process design and parameter selection, analytical process–geometry relationships were established to describe the effects of vibration frequency, feed rate, vibration wavelength, and ball-head geometry on dimple morphology. A critical operating condition was further derived to distinguish discrete dimple formation from continuous groove generation. Experimental validation was conducted on LZ91 magnesium–lithium alloy using a ball radius of 0.25 mm, vibration amplitude of 10 μm, feed rate of 600 mm/min, and excitation frequencies of 5, 15, and 30 Hz. Optical microscopy and surface profilometry confirmed the capability of the proposed process to generate deterministic and periodically distributed micro-dimple arrays. The predicted dimple spacing and width agreed well with experimental measurements, with relative errors below 15%. A larger deviation of approximately 23.8% was observed for indentation depth due to elastic recovery and localized material pile-up. The proposed process provides a practical process–geometry framework for controllable chipless surface texturing and predictable micro-dimple generation.