Study of micro-dimples fabricated on alumina-based ceramics using micro-abrasive jet machining

•Micro-texturing with desired morphology characteristics was firstly explored on ceramics using micro-air jet machining.•The model of abrasive velocity distribution was amended and found to be a good indicator to present the micro-texturing performance.•Introducing micro-patterns on ceramics using micro-AJM is verified to be an effective way to enhance wear resistance in a lubricant system. This paper presents a study of fabricating micro-dimples with desired morphology characteristics using micro-abrasive jet machining. Experiments are conducted under different processing conditions so that blasted dimples with various sizes and geometries could be obtained and analysed. The results indicated that among all the processing factors used in this study, changing processing time and air pressure is found to be the most efficient and controllable way to vary dimple dimension. On the other hand, nozzle stand-off distance and air pressure both play a pivotal role in determining dimple geometry. The results indicate that a variety of desired morphologies on the blasted area could be obtained by optimizing parameter combination. To further reveal the mechanism of shape variation, an amended model of cross-sectional particle velocity distribution is proposed. By correlating the working conditions and the final form of machined micro-structures, the model is confirmed to be an effective indicator to present the machining performance. In the end, friction tests and wear characterization are conducted to verify the positive effect of the introduced micro-texture on improving the lifespan of ceramic-based workpieces.