| 摘要 |
<p>A method is provided for drilling a hole through a metallic workpiece (1) having a thermal barrier coating (3) with a ceramic top coat (2) by laser drilling a counterbore to a depth which extends through the ceramic top coat but not substantially into the metallic workpiece and then laser drilling the hole through the workpiece aligned with the counterbore, the counterbore having a diameter larger than the hole.</p> |
