铍的YAG激光焊接裂纹敏感性研究

分析了激光焊接时为克服焊接裂纹所采取的焊前预热、短焦距焊接及焊接工艺参数等因素对裂纹敏感性的影响。结果表明：选择合适的焊接参数可减少裂纹的产生，但其作用有限，还不能从根本上消除裂纹。焊前预热及焊后缓冷对抑制裂纹作用显著，且随着预热温度提高裂纹率呈下降趋势。此外焊接中减少铍的熔化量对减少裂纹亦发挥了重要作用。

Sensitivity to Cracking of Beryllium by YAG Laser Welding

Effect of preheat, smaller focus spot and welding processing parameter on sensitivity to cracking is studied.Results show that suitable welding parameter can reduce occurrence of cracking, but it is not the most important factor. Preheat before welding and post-heat can obviously diminish welding cracking. As preheat temperature increases, rate of beryllium welding cracking decreases. Moreover, decrease of melted beryllium plays a positive role to restrain sensitivity to cracking.