This example demonstrates an angled hole machined in a silicon carbide ceramic matrix composite (SiC‑CMC) using an ArF excimer laser, featuring a square entrance and a round exit.

The machining sample was a flat SiC‑CMC plate fabricated by the Polymer Infiltration and Pyrolysis (PIP) process. For angled hole machining, the sample surface was tilted at an angle of 20 degrees relative to the optical axis during laser irradiation.

As observed on the sample surface, the entrance of the machined hole has a square shape, while the exit is circular. At both the entrance and the exit, the ratio of the major axis to the minor axis is approximately 3:1, which is consistent with the laser incidence angle of 20 degrees.

The cross-sectional image shows the machined hole after resin embedding and sectioning through the center of the hole for observation. The cross section shows that the hole is inclined at an angle of 20 degrees relative to the sample surface and was formed along the laser incidence direction. In addition, the inner wall geometry of the machined hole shows a square shape near the entrance and a circular shape near the exit, confirming that a shaped hole was successfully formed.