Influence of Blade Gap Thickness and Recoater Velocity on Powder Layer Quality in Additive Manufacturing

Abstract

The mechanical properties of components produced by additive manufacturing processes are the result of the powder layer quality. In powder bed fusion, a more uniform powder layer is necessary for the laser to penetrate the material evenly, building a mechanically stronger part that contains less defects. Research has shown that the powder bed parameters directly influence the powder layer quality. Ideal powder layer quality is defined as having maximum packing density and minimum surface roughness. This study focuses on how the recoating system process impacts the layer quality by varying recoater velocity and blade gap thickness. Inconel 625 powder, with an average particle size of 31.3313μm, is used to study the powder bed parameters. Generally, surface roughness decreased with increasing blade gap thickness, and increased with increasing recoater velocity. Additionally, packing density increased with increasing layer thickness, and decreased with increasing recoater velocity. Linear regression analyses were used to identify exactly what input parameters produce the best layer quality. In conclusion, the most optimum powder layers occur at 𝑉𝑟 = 10mm/s and 𝑡𝑏𝑔=256μm.