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Metallurgical and Materials Transactions A

, Volume 47, Issue 8, pp 3811–3822 | Cite as

Powder Bed Layer Characteristics: The Overseen First-Order Process Input

  • H. W. Mindt
  • M. MegahedEmail author
  • N. P. Lavery
  • M. A. Holmes
  • S. G. R. Brown
Symposium: Additive Manufacturing: Building the Pathway to Process and Material Qualification

Abstract

Powder Bed Additive Manufacturing offers unique advantages in terms of manufacturing cost, lot size, and product complexity compared to traditional processes such as casting, where a minimum lot size is mandatory to achieve economic competitiveness. Many studies—both experimental and numerical—are dedicated to the analysis of how process parameters such as heat source power, scan speed, and scan strategy affect the final material properties. Apart from the general urge to increase the build rate using thicker powder layers, the coating process and how the powder is distributed on the processing table has received very little attention to date. This paper focuses on the first step of every powder bed build process: Coating the process table. A numerical study is performed to investigate how powder is transferred from the source to the processing table. A solid coating blade is modeled to spread commercial Ti-6Al-4V powder. The resulting powder layer is analyzed statistically to determine the packing density and its variation across the processing table. The results are compared with literature reports using the so-called “rain” models. A parameter study is performed to identify the influence of process table displacement and wiper velocity on the powder distribution. The achieved packing density and how that affects subsequent heat source interaction with the powder bed is also investigated numerically.

Keywords

Packing Density Discrete Element Method Powder Layer Processing Table Powder Size Distribution 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Notes

Acknowledgments

The authors acknowledge the financial support of the European Commission 7th Framework Program AMAZE. The authors would like to also thank project partners and collaborators for the ongoing discussions, support, and motivation.

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Copyright information

© The Minerals, Metals & Materials Society and ASM International 2016

Authors and Affiliations

  • H. W. Mindt
    • 1
  • M. Megahed
    • 1
    Email author
  • N. P. Lavery
    • 2
  • M. A. Holmes
    • 2
  • S. G. R. Brown
    • 2
  1. 1.ESI GroupEssenGermany
  2. 2.Swansea UniversitySwanseaUK

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