LASER NEWS

激光焊接能量输入通常用能量密度（激光功率除以光斑面积，单位为 Ｗ／ｃｍ２）和热输入（激光功率除以焊接速度，单位为Ｊ／ｃｍ）表示，前者描述空间范围内激光能量的强度，后者描述时间范围内激光能量的累积。工业使用上一般直接程序编辑波形来设置能量，但是设置的能量和出光检测的能量以及最后焊接头出来的功率有一定损耗。这其中我们要注意关注能量而非功率，不同的场景焊接形式功率波形会有不同，但是能量相对比较准确，有对比价值。不同材料的熔化能量的积累有利于快速针对新产品进行工艺窗口设计，快速定位合理参数。简单的功率与熔深熔宽的关系如图，一般来说：功率越大，熔深熔宽都会随功率增加而增大。激光焊接有一个能量节点，低于节

The welding process parameter—speed refers to the speed at which the welding arc or welding wire moves. It is a critical parameter affecting weld quality and welding efficiency. The choice of welding speed directly impacts the formation and maintenance of the weld pool, as well as the physical and chemical properties of the weld joint.

In laser welding under keyhole mode, a specific audible sound in a certain frequency range is emitted. When deep penetration laser welding cannot proceed due to certain reasons or during conduction welding, this characteristic audible signal decreases or disappears. It is generally believed that this sound signal is caused by pressure waves generated when metal vapor or plasma jets out from the keyhole. This signal is closely related to the behavior of the plasma, keyhole, and weld pool, reflecting changes in the welding process.

This article reviews the current research status and development trends of quality inspection technologies in laser welding processes, analyzing in-depth the applications and characteristics of different sensing technologies in laser welding quality control. Laser welding, as an efficient and precise welding technology, plays a crucial role in improving product quality and reducing defect occurrence. Research indicates that by real-time monitoring key parameters during laser welding, such as melt pool size, weld bead formation rate, and plasma behavior, welding defects can be effectively predicted and controlled, ensuring welding quality.