| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To perform finishing process in a shorter time while finishing process accuracy is enhanced for the inner wall of a prepared hole. <P>SOLUTION: After a prepared hole 23L is drilled in a workpiece 23, the inner wall (solidification part 23k) of this prepared hole 23L is irradiated with a picosecond laser beam 17 to make a smooth finish on the inner wall. In the picosecond laser beam 17, energy density can be made greater compared with a conventional finishing process by electric discharge machining. When the picosecond laser beam 17 is emitted to the workpiece 23, the temperature of the irradiation part of the workpiece 23 becomes high instantaneously, enabling the finishing process to be performed in a shorter time. In addition, the pulse width T4 of the picosecond laser beam 17 is very small, that is, the irradiation time of the picosecond laser beam 17 is very short, which tends to suppress rise in temperature in a part near the irradiation part of the picosecond laser beam 17. As a result, there is less tendency of causing a heat-affected zone, which improves finishing accuracy of the inner wall of the prepared hole 23L to make the inner wall smoother. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
