A theoretical and experimental investigation of particle embedding and erosion behaviour of PDMS in micro-abrasive air-jet machining

Embedding of abrasive particles can be an unwanted consequence of micro-abrasive air-jet machining (MAJM) of polydimethylsiloxane (PMDS). In this work, the extent to which the abrasive is embedded is analyzed quantitatively by a modeling analysis involving the impact velocity, impact force, and erosion depth of the single abrasive particle on PDMS combined with the change in the material erosion removal rate. In addition, the surface morphology of PDMS was characterized under different erosion processing. The results show that the wear mechanisms is characterized by a transition from microcutting to indentation and surface fatigue, with increasing impact angle. In general, small impact angle and high air pressures are recommended to avoid embedding of abrasive particles, and the appearance of metamorphic layer. The theoretical analysis and experimental results provide potential benefits in predicting the erosion depth of the single abrasive particle and controlling the embedding of abrasive particles during machining of PDMS.