1 0 0 0 OA アーク溶接における表面温度情報を用いた溶込み深さの推定
- 著者
- 野村 和史 山下 隼 井村 文哉 浅井 知
- 出版者
- 一般社団法人 溶接学会
- 雑誌
- 溶接学会論文集 (ISSN:02884771)
- 巻号頁・発行日
- vol.36, no.4, pp.264-273, 2018 (Released:2018-11-15)
- 参考文献数
- 28
- 被引用文献数
- 2
This study proposed the estimation method of the depth of wed penetration using the experimental measurement of the weld pool shape and the temperature on the front surface during the welding. This method is based on the simple heat conduction calculation, and does not require a flow-field calculation and a heat input information as seen in various welding simulations. In this paper, we first examined the applicability of this method to a bead on plate welding. As a result of application to TIG and A-TIG welding with SUS304 base metal, we obtained the estimated depth with an error of +14∼30% to the actual depth. We investigated this experimental result by the analytical heat conduction model, and found that utilizing the surface temperature with wider area has a possibility to estimate the depth with higher precision.
1 0 0 0 OA 非線形光学結晶による第二高調波発生の温度依存性に関する理論的解析
- 著者
- 大村 悦二 野村 和史 宮本 勇
- 出版者
- 一般社団法人 溶接学会
- 雑誌
- 溶接学会論文集 (ISSN:02884771)
- 巻号頁・発行日
- vol.21, no.3, pp.344-349, 2003 (Released:2004-11-16)
- 参考文献数
- 5
In recent years, applications of solid-state lasers with frequency conversion techniques such as SHG, THG and FHG to precision microfabrication progress rapidly. When nonlinear optical crystal used for frequency conversion absorbs laser beam, temperature of the crystal rises, and the frequency-conversion efficiency decreases. In this study, KH2PO4, that is potassium dihydrogen phosphate (KDP), whose physical properties are well known was supposed as a nonlinear optical crystal for SHG. Temperature dependence of frequency-conversion efficiency was examined theoretically by solving the coupling problem composed of heat conduction equation and complex amplitude equations, which are derived considering the absorption of laser in the crystal. The temperature change of the crystal induced by Nd:YAG laser absorption, the local change of refractive indices, and the consequential variation of SHG frequency-conversion efficiency were analyzed for single and repetitive pulses. As a result, the temperature dependence of frequency-conversion became clear quantitatively. Remarkable inverse-conversion of SHG also appears for the repeated laser irradiation with high power density.