CW laser drilling of composite ceramics

Abstract

Laser drilling continues to enjoy great popularity as a quick way to drill holes, especially for aerospace applications. In the past, much effort has been directed at understanding laser drilling of metals. The present study discusses the utilization of the laser drilling process to drill holes in composite ceramics. The minimum time required to drill through 2mm thick specimens was experimentally determined for two different continuous fiber ceramic matrix composites for different powers and focusing conditions. An accurate model for calculating drill-through times, top and bottom diameters, taper etc, is presented. The results of the model are compared with experimental results for drill-through times. The results indicate that accurate measurements of thermophysical properties at high temperatures combined with extensive hole drilling experimental measurements are necessary to make accurate predictions for laser drilling.Laser drilling continues to enjoy great popularity as a quick way to drill holes, especially for aerospace applications. In the past, much effort has been directed at understanding laser drilling of metals. The present study discusses the utilization of the laser drilling process to drill holes in composite ceramics. The minimum time required to drill through 2mm thick specimens was experimentally determined for two different continuous fiber ceramic matrix composites for different powers and focusing conditions. An accurate model for calculating drill-through times, top and bottom diameters, taper etc, is presented. The results of the model are compared with experimental results for drill-through times. The results indicate that accurate measurements of thermophysical properties at high temperatures combined with extensive hole drilling experimental measurements are necessary to make accurate predictions for laser drilling.