Effects of Nd: YAG Pulsed Laser Beam Parameters on Microstructure and Dimensions of Weld Pool for a Copper-Beryllium Plate

The Nd:YAG pulsed laser welded structure of Copper-Beryllium alloy were studied by varying laser parameters such as pulse energy, spot diameter, duration and frequency. The metallographic results showed that the pulse energy should be kept as low as possible in order to obtain the weld pool with the highest values of penetration and the least width. Low pulse energy decreases the time for segregation of impurities. The impurities are the main cause of hot cracking. In addition, the laser spot diameter should be kept as low as possible. Moreover, the microscopic investigations demonstrate that the dendrite structure prevails in weld pool near the weld centerline and the cellular structure forms in weld pool near the base meal.