Additive Manufacturing with aluminium alloys is a subject of increasing industrial interest. Directed Energy Deposition using high power lasers and a powder feed is a useful option but the interactions between the powder stream and the laser beam are not completely understood. It is well known that the powder particles heat up in the laser beam and some theoretical models predict that they can reach their vaporisation temperature and have their flight path altered by the associated recoil pressure. In order to learn more about these phenomena, powder streams were observed with a high-speed camera at different laser powers (up to 6 kW) and with three batches of powder (AlSi10Mg) of different particle sizes. The results showed an increase of powder focussing with increased laser power. In addition, some particles were found to disintegrate in the laser beam. It is demonstrated that particle disintegration is most likely to be caused by the momentum induced by the recoil pressure.

用铝合金进行增材制造是日益增长的工业兴趣的主题。使用高功率激光器和粉末进料进行定向能量沉积是一个有用的选择，但粉末流与激光束之间的相互作用尚不完全清楚。众所周知，粉末颗粒会在激光束中加热，一些理论模型预测它们可以达到其汽化温度，并且其飞行路径会因相关的反冲压力而改变。为了了解更多有关这些现象的信息，使用高速相机以不同的激光功率（最多6倍）观察了粉末流。 kW）并使用三批不同粒径的粉末（AlSi10Mg）。结果表明，随着激光功率的增加，粉末聚焦的增加。另外，发现一些颗粒在激光束中分解。结果表明，粒子的分解最有可能是由反冲压力引起的动量引起的。