Improvement of Geometrical Accuracy of Micro Holes Machined Through Micro Abrasive Jet Machining

Assembling of various parts and subassembly needs the closer attention on the geometrical accuracy of the part apart from the dimensional tolerances. Micro holes machined through micro abrasive jet machining are tapered, resulting in poor cylindricity. Cylindricity of the machined micro holes can be improved by reducing the taper angle of the hole. This paper presents a novel approach for machining holes on brittle material-quartz, using the in-house developed micro abrasive jet machine, wherein the nozzle is given a feed rate equal to the average rate of change of the workpiece thickness. The experiments are conducted to study the effect of this novel approach to the shape of the machined hole by measuring the entrance diameter and exit diameter and hence calculated the taper angle. The obtained experimental results reveals that the taper angle of the machined hole is reduced by approximately 58% using this novel approach and hence achieved the improvement in cylindricity of the machined holes.