Cryogenic Abrasive Jet Machining of Polydimethylsiloxane and Polytetrafluoroethylene at Different Temperatures

The temperature dependence of the solid particle erosion of polydimethylsiloxane (PDMS), polytetrafluoroethylene (PTFE) and high carbon steel using aluminum oxide particles was investigated. The most efficient machining of PDMS occurred at approximately -178°C, at angles of attack between 30° and 60°. Although it was demonstrated that PDMS could be machined at temperatures above its glass transition, the erosion rate increased by a factor of more than 10 when the machining temperature was below this point. The maximum erosion in PTFE occurred at the coldest temperature of -177°C between the angles of 30 and 90°. This scenario improved the erosion rate by more than a factor of five. The erosion rate in high carbon steel was increased approximately twofold when lowering the temperature from 17°C to -177°C. The surface evolution results presented can be used to predict feature shapes both polymers while minimizing cooling costs, minimizing mask wear or maximizing substrate erosion.