Investigation into micro abrasive intermittent jet machining

In the machining of small holes by the conventional micro abrasive jet machining, the colliding abrasives accumulate in the bottom of the hole, preventing the direct impact of successive abrasives onto the workpiece. As a result, the machining efficiency decreases as the machining progresses. This paper introduces a new method of micro abrasive jet machining, called micro abrasive intermittent jet machining (MAIJM), in which there exists a period of time during which no abrasive is injected into the gas stream from the nozzle so that the continuous flow of gas without abrasives from the nozzle could blow away any abrasives that have accumulated in the hole. Empirical models are developed for evaluation of the effect of MAIJM process parameters on the shape of the machined holes by proper design of experiments based on a Taguchi orthogonal array and by multi-variable linear regression. Further experiments are conducted to confirm the validity of the developed statistical model by comparing the model predictions with the experimental results.