[18a-136-1~12] 3.7 Laser processing

[18a-136-6] Optimized laser pulse irradiation for laser drilling to avoide collision with ablated jet flow in super critical carbon dioxide.

Yuki Kitahara¹, Yuto Okada¹, Anna Ito², Hiromasa Furuta², 〇(PC)Keisuke Yoshiki¹ (1.Univ. of Hyogo, 2.Panasonic Industrial Devices SUNX Co., Ltd.)

Keywords:Supercritical fluid, Carbon dioxide, Laser drilling

Rayleigh number of super critical carbon dioxide (scrCO₂) is controllable by its pressure and temperature. Since, the disadvantages of convection are more apparent than advantages in processing of opaque materials, the Rayleigh number should be reduced by using gas-like scrCO₂.
In this report, we suggest optimized irradiation method to suppress the disadvantages of convection. As the result, we obtained holes which have deeper depth and higher aspect ratio in drilling by liquid-like scrCO₂.