| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide the consistency to a cooling process in a method of forming a vent crack in a brittle material. <P>SOLUTION: The method includes: heating a surface of the brittle material with a laser along a predetermined path; and cooling the heated surface of the brittle material with a coherent stream 28 of cooling liquid 22 dispensed by a nozzle 24. The coherent stream 28 has a coherence length equal to or greater than 50 mm and a diameter in the range from about 70 to about 200μm. A working distance between an aperture 30 of the nozzle 24 and the surface of the brittle material is less than the coherence length of the coherent stream 28. The coherent stream 28 of cooling liquid 22 is formed by a convergent nozzle with a circularly symmetric aperture or a nozzle having a straight walled cylindrical orifice. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
