Powder Layer Preparation by Novel Gravity-Based Powder Spreading System for Additive Manufacturing
摘要
The demand for producing industrial-grade metallic parts using AM technique is increasing day-by-day. Powder bed fusion (PBF) process appears to be one of the promising techniques to achieve this. Spreading a smooth layer with high repeatability is the primary requirement for PBF process. The effective layering process determines the mechanical characteristics of the finished product. The powder layer is often applied with a roller or a doctor blade. In the current study, a novel gravity-based non-contact type method is proposed for spreading the powder layer. To understand the capability of the system, a miniaturized model is simulated on Altair EDEM® software. The system comprises a hopper, when subjected to vibration will dispense powder through a narrow opening present beneath the hopper. The hopper is subjected to movement in the appropriate direction, and thus, a powder layer can be formed on the bed present below the hopper. The system is first tested for different values of amplitudes. After analyzing the effect of amplitude, the system is tested for different frequencies also. A mass sensor is placed on the bed which is used to check the uniformity of the layer on the bed. The system appears to be in an unsteady state but after a certain time duration, the system goes into a steady state. Mass flow analysis of the bed reveals that the layer forming on the bed appears to be uniform in nature.