Analysis of Build Direction in Deposition-Based Additive Manufacturing of Overhang Structures

Leu²

2023

Preprint

As the extensive research in Additive Manufacturing (AM) shows, the powder characteristics, such as particle size and geometry, play an important role in determining the quality of powder layer and part fabricated with powder-based AM processes. It has been found that spherical particles result in better powder flowability and spreadability. An attempt to improve particle sphericity is to process the powder using the plasma spheroidization process, where the particles heat up, melt, and reshape to spheres. Several research works have been conducted to study the plasma spheroidization process and understand particle-plasma reactions. Although researchers have turned to simulations to overcome the difficulty of experimental study of such reactions, they only sufficed to characterize the powder particle size without evaluating the particle geometries. In this work, the plasma spheroidization process of copper powder was numerically examined to assess the impact of plasma spheroidization process on powder geometry and particle size. For the first time in literature, a method was proposed to quantify the particle geometry at each particle residence time. The results of simulation matched well with those of experiments.

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Numerical Study and Experimental Validation of Copper Powder Plasma Spheroidization Process

Leu²

2023

Preprint

“…The nal component is fabricated by repeating the material injection and production process for all part's layers [8]. Due to this layer-by-layer manufacturing process, the fabrication of high-complex geometry components with high accuracy and desirable part properties is possible [9][10][11][12].…”

Section: Introductionmentioning

confidence: 99%

Experimental approach for development of a powder spreading metric in additive manufacturing

Int J Adv Manuf Technol

Sutton

Yates

et al. 2023

The powder spreading is a vital step of powder-based Additive Manufacturing (AM) processes. The quality of spread powder can considerably in uence the properties of fabricated parts. Poorly-packed powder beds with high surface roughness result in printed part layers with large porosity and low dimensional accuracy, leading to poor mechanical properties. Therefore, the powder spreadability and its dependence on process parameters and powder characteristics should be quanti ed to improve the e ciency of powder-based AM methods. This study proposes a novel dimensionless powder spreadability metric that can be commonly used in different powder-based AM processes. The quality of spread powder in terms of powder bed density and surface roughness was evaluated by adjusting the process parameters, including recoating velocity and layer thickness, and powder characteristics, including particle size distribution. In addition, the dynamic repose angle was proposed and examined as another powder spreadability metric. The results showed that these two proposed metrics were strongly correlated, and lower recoating velocity and larger layer thickness led to higher spreadability and lower dynamic repose angle.

Section: Introductionmentioning

confidence: 99%

Experimental Approach for Development of a Powder Spreading Metric in Additive Manufacturing

Sutton²,

Yates³

et al. 2022

Preprint

The powder spreading is a vital step of powder-based Additive Manufacturing (AM) processes. The quality of spread powder can considerably influence the properties of fabricated parts. Poorly-packed powder beds with high surface roughness result in printed part layers with large porosity and low dimensional accuracy, leading to poor mechanical properties. Therefore, the powder spreadability and its dependence on process parameters and powder characteristics should be quantified to improve the efficiency of powder-based AM methods. This study proposes a novel dimensionless powder spreadability metric that can be commonly used in different powder-based AM processes. The quality of spread powder in terms of powder bed density and surface roughness was evaluated by adjusting the process parameters, including recoating velocity and layer thickness, and powder characteristics, including particle size distribution. In addition, the dynamic repose angle was proposed and examined as another powder spreadability metric. The results showed that these two proposed metrics were strongly correlated, and lower recoating velocity and larger layer thickness led to higher spreadability and lower dynamic repose angle.