A Simulation Study on Sieving as a Powder Deposition Method in Powder Bed Fusion Processes

Area of Science:

• Materials Science
• Manufacturing Engineering
• Additive Manufacturing

Background:

• Even powder layers are crucial for powder bed fusion (PBF) processes.
• Powder sieving is typically used for pre-processing, not direct deposition.

Purpose of the Study:

• To investigate sieving as a powder deposition method in PBF.
• To optimize sieving parameters for improved powder flow and layer quality.
• To compare controlled sieving with conventional recoating techniques.

Main Methods:

• Developed and validated a discrete element method (DEM) powder model.
• Employed Taguchi design of experiments and analysis of variance (ANOVA) for optimization.
• Evaluated layer quality using surface roughness, layer thickness deviation, surface coverage, and packing density.

Main Results:

• Optimized sieving parameters include oscillating frequency and amplitude, influenced by initial powder load.
• Sieve aperture shape impacts mass flow; polygons with more sides reduce mass flow per aperture.
• Controlled sieving demonstrated superior layer surface quality and deposition duration compared to a doctor blade recoater.

Conclusions:

• Controlled sieving is a viable and effective method for powder deposition in PBF.
• Optimized sieving parameters can significantly enhance powder flow and layer homogeneity.
• This technique offers advantages over traditional recoating for improved part quality and process efficiency.