Fatigue and Failure Analysis of an Additively Manufactured Contemporary Aluminum Alloy

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

Int J Adv Manuf Technol

Sutton

Yates

et al. 2023

“…5,6,7 Powder material as the feedstock for several additive manufacturing processes is important from various viewpoints, such as powder flow properties, impact on the mechanical properties of fabricated parts, and economic consideration. 8,9 In the laser powder bed fusion (LPBF) process the feedstock material is in the form of powder with some specific characteristics such as particle size and size distribution, particle geometry, and powder flowability. 10 Also, recently, powder spreadability, which is a function of all the mentioned powder characteristics, has been found to play an important role in the LPBF process.…”

Section: Introductionmentioning

confidence: 99%

Investigation of Mechanical Properties of Parts Fabricated with Gas- and Water-Atomized 304L Stainless Steel Powder in the Laser Powder Bed Fusion Process

Sutton

Hung

et al. 2021

JOM

The use of gas-atomized powder as the feedstock material for the laser powder bed fusion (LPBF) process is common in the additive manufacturing (AM) community. Although gas-atomization produces powder with high sphericity, its relatively expensive production cost is a downside for application in AM processes. Water atomization of powder may overcome this limitation due to its low cost relative to the gas-atomization process. In this work, gas-and water-atomized 304L stainless steel powders were morphologically characterized through scanning electron microscopy (SEM). The water-atomized powder had a wider particle size distribution and exhibited less sphericity. Measuring powder flowability using the Revolution Powder Analyzer (RPA) indicated that the water-atomized powder had less flowability than the gasatomized powder. Through examining the mechanical properties of LPBF fabricated parts using tensile tests, the gas-atomized powder had significantly higher yield tensile strength and elongation than the water-atomized powder; however, their ultimate tensile strengths were not significantly different.

“…There is debate, however, as to the suitability of objects made using FDM as accurate representations of their production counterparts, in the realm of either AM or traditional manufacturing processes [11] [12] [13] [14]. As FDM necessitates forming polymer lament into layers, the mechanical behavior under loading of the object at the layer boundaries may differ from the bulk behavior of the polymer that the part is composed of, making the part's loading behavior anisotropic [15][16].…”

Section: Introductionmentioning

confidence: 99%

Verification of Stress Transformation in Anisotropic Material Additively Manufactured by Fused Deposition Modeling (FDM)

Mahdianikhotbesara

Yadegari

2021

Preprint

The widespread use of Additive Manufacturing (AM) has been extensively progressed in the past decade due to the convenience provided by AM in rapid and reliable part production. Fused Deposition Modeling (FDM) has witnessed even faster growth of application as its equipment is environmentally-friendly and easily adaptable. This increased use of FDM to manufacture prototypes and finished parts is accompanied by concerns that 3D printed parts do not perform the same as relatively homogeneous parts produced by molding or machining. As the interface between two faces of bonded material may be modeled by stress elements, in theory by modeling 3D printed layers subjected to tension at varying angles as transformed stress elements, the stress required to break the layer bonds can be determined. To evaluate such a relationship, in this study, the stresses calculated from stress transformation were compared with the behavior of 3D printed specimens subjected to tensile loads.