scholarly journals A Novel Framework for Predictive Modeling and Optimization of Powder Bed Fusion Process

2021 ◽  
Author(s):  
Ehsan Malekipour ◽  
Mallikharjun Marrey ◽  
Hazim El-Mounayri ◽  
Eric Faierson ◽  
Mangilal Agarwal
Keyword(s):  
Mechanical Properties ◽  
Process Parameters ◽  
Support Vector ◽  
Large Set ◽  
Powder Bed Fusion ◽  
Two Phase ◽  
Powder Bed ◽  
Steel Material ◽  
Wide Range ◽  
The Impact

Powder bed fusion (PBF) process is a metal additive manufacturing process which can build parts with any complexity from a wide range of metallic materials. PBF process research has predominantly focused on the impact of only a few parameters on product properties due to the lack of a systematic approach for optimizing a large set of process parameters simultaneously. The pivotal challenges regarding this process require a quantitative approach for mapping the material properties and process parameters onto the ultimate quality; this will then enable the optimization of those parameters. In this study, we propose a two-phase framework for optimizing the process parameters and developing a predictive model for 316L stainless steel material. We also discuss the correlation between process parameters -- i.e., laser specifications -- and mechanical properties and how to achieve parts with high density (> 98%) as well as better ultimate mechanical properties. In this paper, we introduce and test an innovative approach for developing AM predictive models, with a relatively low error percentage of 10.236% that are used to optimize process parameters in accordance with user or manufacturer requirements. These models use support vector regression, random forest regression, and neural network techniques. It is shown that the intelligent selection of process parameters using these models can achieve an optimized density of up to 99.31% with uniform microstructure, which improves hardness, impact strength, and other mechanical properties.

scholarly journals Control of Crystallographic Texture and Mechanical Properties of Hastelloy-X via Laser Powder Bed Fusion

Crystals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1064
Author(s):  
Shinya Hibino ◽  
Tsubasa Todo ◽  
Takuya Ishimoto ◽  
Ozkan Gokcekaya ◽  
Yuichiro Koizumi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Process Parameters ◽  
Crystallographic Texture ◽  
Lamellar Microstructure ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Hastelloy X ◽  
Single Crystalline ◽  
Powder Bed ◽  
Wide Range

The influence of various laser powder bed fusion (LPBF) process parameters on the crystallographic textures and mechanical properties of a typical Ni-based solid-solution strengthened alloy, Hastelloy-X, was examined. Samples were classified into four groups based on the type of crystallographic texture: single crystalline-like microstructure with <100>//build direction (BD) (<100>-SCM), single crystalline-like microstructure with <110>//BD (<110>-SCM), crystallographic lamellar microstructure (CLM), or polycrystalline microstructure (PCM). These four crystallographic textures were realized in Hastelloy-X for the first time here to the best of our knowledge. The mechanical properties of the samples varied depending on their texture. The tensile properties were affected not only by the Schmid factor but also by the grain size and the presence of lamellar boundaries (grain boundaries). The lamellar boundaries at the interface between the <110>//BD oriented main layers and the <100>//BD-oriented sub-layers of CLM contributed to the resistance to slip transmission and the increased proof stress. It was possible to control a wide range of crystallographic microstructures via the LPBF process parameters, which determines the melt pool morphology and solidification behavior.

scholarly journals On the Impact of Build Envelope Sizes on E-PBF Processed Pure Iron

2021 ◽  
Author(s):  
C. J. J. Torrent ◽  
P. Krooß ◽  
T. Niendorf
Keyword(s):  
Mechanical Properties ◽  
Electron Beam ◽  
Additive Manufacturing ◽  
Thermal History ◽  
Powder Bed Fusion ◽  
Parameter Setting ◽  
Powder Bed ◽  
History Of ◽  
Specific Temperature ◽  
The Impact

AbstractIn additive manufacturing, the thermal history of a part determines its final microstructural and mechanical properties. The factors leading to a specific temperature profile are diverse. For the integrity of a parameter setting established, periphery variations must also be considered. In the present study, iron was processed by electron beam powder bed fusion. Parts realized by two process runs featuring different build plate sizes were analyzed. It is shown that the process temperature differs significantly, eventually affecting the properties of the processed parts.

Quasicrystalline Composites by Additive Manufacturing

2019 ◽  
Vol 818 ◽  
pp. 72-76 ◽  
Author(s):  
Konda Gokuldoss Prashanth ◽  
Sergio Scudino
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Selective Laser Melting ◽  
Process Parameters ◽  
Complex Shape ◽  
Powder Bed Fusion ◽  
Laser Melting ◽  
Powder Bed ◽  
Novel Materials ◽  
Tunable Properties

Laser based powder bed fusion (LBPF) or selective laser melting (SLM) is making a leap march towards fabricating novel materials with improved functionalities. An attempt has been made here to fabricate hard quasicrystalline composites via SLM, which demonstrates that the process parameters can be used to vary the phases in the composites. The mechanical properties of the composite depend on their constituents and hence can be varied by varying the process parameters. The results show that SLM not only produces parts with improved functionalities and complex shape but also leads to defined phases and tunable properties.

scholarly journals Influences of Process Parameters on the Microstructure and Mechanical Properties of CoCrFeNiTi Based High-Entropy Alloy in a Laser Powder Bed Fusion Process

Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 549
Author(s):  
Takafumi Ikeda ◽  
Makiko Yonehara ◽  
Toshi-Taka Ikeshoji ◽  
Tohru Nobuki ◽  
Minoru Hatate ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Surface Roughness ◽  
Process Parameters ◽  
Laser Power ◽  
Powder Bed Fusion ◽  
Process Map ◽  
Powder Bed ◽  
High Entropy ◽  
Scan Speed ◽  
Fabrication Condition

Recently, high-entropy alloys (HEAs) have attracted much attention because of their superior properties, such as high strength and corrosion resistance. This study aimed to investigate the influences of process parameters on the microstructure and mechanical properties of CoCrFe NiTiMo HEAs using a laser-based powder bed fusion (LPBF) process. In terms of laser power and scan speed, a process map was constructed by evaluating the density and surface roughness of the as-built specimen to optimize the process parameters of the products. The mechanical properties of the as-built specimens fabricated at the optimum fabrication condition derived from the process map were evaluated. Consequently, the optimum laser power and scan speed could be obtained using the process map evaluated by density and surface roughness. The as-built specimen fabricated at the optimum fabrication condition presented a relative density of more than 99.8%. The microstructure of the as-built specimen exhibited anisotropy along the build direction. The tensile strength and elongation of the as-built specimen were around 1150 MPa and more than 20%, respectively.

scholarly journals Additive Manufacturing of Polypropylene: a Screening Design of Experiment Using Laser-Based Powder Bed Fusion

2018 ◽  
Author(s):  
Inigo Flores Ituarte ◽  
Olli Wiikinkoski ◽  
Anton Jansson
Keyword(s):  
Additive Manufacturing ◽  
Process Parameters ◽  
Design Of Experiment ◽  
Manufacturing Industry ◽  
Tensile Elongation ◽  
Scanning Speed ◽  
Process Window ◽  
Powder Bed Fusion ◽  
Powder Bed ◽  
The Impact

The use of commodity polymers such as polypropylene (PP) is key to open new market segments and applications for the additive manufacturing industry. Technologies such as powder-bed fusion (PBF) can process PP powder; however, much is still to learn concerning process parameters for reliable manufacturing. This study focusses in the process-property relationships of PP using laser-based PBF. The research presents an overview of the intrinsic and the extrinsic characteristic of a commercial PP powder as well as fabrication of tensile specimens with varying process parameters to characterize tensile, elongation at break, and porosity properties. The impact of key process parameters, such as power and scanning speed are systematically modified in a controlled design of experiment. The results were compared to the existing body of knowledge; the outcome is to present a process window and optimal process parameters for industrial use of PP. The computer tomography data revealed a highly porous structure inside specimens ranging between 8.46% and 10.08%, with porosity concentrated in the interlayer planes in the build direction. The results of the design of experiment for this commercial material show a narrow window of 0.122 &ge; Ev &ge; 0.138 J/mm3 led to increased mechanical properties while maintaining geometrical stability.

scholarly journals Spreading of Powders in Powder Bed Additive Manufacturing: an Experimental Approach

2021 ◽  
Author(s):  
Valerio Lampitella ◽  
Marco Trofa ◽  
Antonello Astarita ◽  
Gaetano D’Avino
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Process Parameters ◽  
Experimental Approach ◽  
Physical Mechanism ◽  
Industrial Applications ◽  
Powder Bed Fusion ◽  
Spreading Process ◽  
Powder Bed ◽  
Optimal Window

Powder bed additive manufacturing allows for the production of fully customizable parts and is of great interest for industrial applications. However, the repeatability of the parts and the uniformity of the mechanical properties are still an issue. More specifically, the physical mechanism of the spreading process of the powders, which significantly affects the characteristics of the final part, is not completely understood. In powder bed fusion technologies, the spreading is performed by a device, typically a roller or a blade, that collects the powders from the feedstock and successively deposits them in a layer of several dozens of microns that is then processed with a laser beam. In this work, an experimental approach is developed and employed to study the powder spreading process and analyze in detail the motion of the powders from the accumulation zone to the deposition stage. The presented experiments are carried out on a home-made device that reproduces the spreading process and enables the measurement of the characteristics of the powder bed. Furthermore, the correlation with the process parameters, e.g., the speed of the spreading device, is also investigated. These results can be used to obtain useful insights on the optimal window for the process parameters.

scholarly journals Additive Manufacturing of Polypropylene: A Screening Design of Experiment Using Laser-Based Powder Bed Fusion

Polymers ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1293 ◽  
Author(s):  
Iñigo Flores Ituarte ◽  
Olli Wiikinkoski ◽  
Anton Jansson
Keyword(s):  
Additive Manufacturing ◽  
Process Parameters ◽  
Design Of Experiment ◽  
Manufacturing Industry ◽  
Tensile Elongation ◽  
Scanning Speed ◽  
Process Window ◽  
Powder Bed Fusion ◽  
Powder Bed ◽  
The Impact

The use of commodity polymers such as polypropylene (PP) is key to open new market segments and applications for the additive manufacturing industry. Technologies such as powder-bed fusion (PBF) can process PP powder; however, much is still to learn concerning process parameters for reliable manufacturing. This study focusses in the process–property relationships of PP using laser-based PBF. The research presents an overview of the intrinsic and the extrinsic characteristic of a commercial PP powder as well as fabrication of tensile specimens with varying process parameters to characterize tensile, elongation at break, and porosity properties. The impact of key process parameters, such as power and scanning speed, are systematically modified in a controlled design of experiment. The results were compared to the existing body of knowledge; the outcome is to present a process window and optimal process parameters for industrial use of PP. The computer tomography data revealed a highly porous structure inside specimens ranging between 8.46% and 10.08%, with porosity concentrated in the interlayer planes in the build direction. The results of the design of experiment for this commercial material show a narrow window of 0.122 ≥ Ev ≥ 0.138 J/mm3 led to increased mechanical properties while maintaining geometrical stability.

scholarly journals A Critical Review on Effect of Process Parameters on Mechanical and Microstructural Properties of Powder-Bed Fusion Additive Manufacturing of SS316L

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6527
Author(s):  
Meet Gor ◽  
Harsh Soni ◽  
Vishal Wankhede ◽  
Pankaj Sahlot ◽  
Krzysztof Grzelak ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Process Parameters ◽  
Heating Temperature ◽  
Detailed Comparison ◽  
Process Parameter ◽  
Layer By Layer ◽  
Powder Bed Fusion ◽  
Powder Bed ◽  
Practical Applications

Additive manufacturing (AM) is one of the recently studied research areas, due to its ability to eliminate different subtractive manufacturing limitations, such as difficultly in fabricating complex parts, material wastage, and numbers of sequential operations. Laser-powder bed fusion (L-PBF) AM for SS316L is known for complex part production due to layer-by-layer deposition and is extensively used in the aerospace, automobile, and medical sectors. The process parameter selection is crucial for deciding the overall quality of the SS316L build component with L-PBF AM. This review critically elaborates the effect of various input parameters, i.e., laser power, scanning speed, hatch spacing, and layer thickness, on various mechanical properties of AM SS316L, such as tensile strength, hardness, and the effect of porosity, along with the microstructure evolution. The effect of other AM parameters, such as the build orientation, pre-heating temperature, and particle size, on the build properties is also discussed. The scope of this review also concerns the challenges in practical applications of AM SS316L. Hence, the residual stress formation, their influence on the mechanical properties and corrosion behavior of the AM build part for bio implant application is also considered. This review involves a detailed comparison of properties achievable with different AM techniques and various post-processing techniques, such as heat treatment and grain refinement effects on properties. This review would help in selecting suitable process parameters for various human body implants and many different applications. This study would also help to better understand the effect of each process parameter of PBF-AM on the SS316L build part quality.

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