A study on the Optimum Conditions of Nd:YAG LBW for Zircaloy-4 End Cap Closure By Optical Fiber Transmission

광섬유전송에 의한 Zircaloy-4 봉단마개밀봉의 Nd:YAG LBW의 최적조건에 관한 연구

This study is to investigate the optimum conditions of Nd:YAG laser beam welding for Zircaloy-4 end cap closure by optical fiber transmission. Laser welding parameters which affect the penetration depth and bead width were experimentally examined using the various beam radius by the beam quality analyzer, joint geometries of end cap and the laser parameters which mean pulse width, repetition rate and pulse energy. Also, an optimum welding speed and the effect of assistant gas with varying the flow rate of He were investigated. We found that the laser average power for the end cap welding will be 230W and rotation speed must not exceed 8 RPM, the best position of focus using optical fiber with 600.mu.m will be 2 to 3mm below the surface of the material.