Continuous feeding of powders with vibration and pneumatic pressure assistance for laser-based additive manufacturing processes

摘要

Continuous feeding of powders is critical to ensure manufacturing quality in laser-based additive manufacturing processes. However, current powder delivery systems are either not capable of continuous feeding of powders or cannot guarantee that the powders achieve a certain motion velocity to assure their uninterrupted motion into the melt pool. Therefore, a new powder delivery system is developed which use the advantages of vibration and pneumatic feeders. In this powder delivery system, vibration is used to disperse agglomerated powders and control the powder federate while pneumatic pressure is used to increase powder velocity to guarantee that the powder enters the melt pool. Powder flow simulation has been conducted to reveal powder flow characteristics. To test the feasibility of the developed powder delivery system for powder delivery and verify the correctness of powder flow simulation results, powder delivery experiments have been conducted. Effects of argon gas flowrate and vibration parameters on powder flowrate have been investigated. Experimental results show that a stable and repeatable powder flowrate can be controlled by adjusting the vibration parameters and the argon gas flowrate with the developed delivery system.