scholarly journals Transient Simulation of Particle Transport and Deposition in the Laser Powder Bed Fusion Process: A new Approach to Model Particle and Heat Ejection from the Melt Pool

2021 ◽  
pp. 102135
Author(s):  
J. Altmeppen ◽  
R. Nekic ◽  
P. Wagenblast ◽  
S. Staudacher
Keyword(s):  
Particle Transport ◽  
Transient Simulation ◽  
Fusion Process ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
New Approach ◽  
Powder Bed ◽  
Model Particle ◽  
Melt Pool

Vision-based in-situ monitoring system for melt-pool detection in laser powder bed fusion process

2021 ◽  
Vol 68 ◽  
pp. 1735-1745
Author(s):  
Trong-Nhan Le ◽  
Min-Hsun Lee ◽  
Ze-Hong Lin ◽  
Hong-Chuong Tran ◽  
Yu-Lung Lo
Keyword(s):  
Monitoring System ◽  
In Situ Monitoring ◽  
Fusion Process ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Powder Bed ◽  
Melt Pool

Transient Melt Pool Formation in Laser-Powder Bed Fusion Process

2020 ◽  
Author(s):  
Santosh Rauniyar ◽  
Kevin Chou
Keyword(s):  
Steady State ◽  
Transient State ◽  
Fusion Process ◽  
Quasi Steady State ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Powder Bed ◽  
Melt Pool ◽  
Scan Speed ◽  
Powder Particles

Abstract Parts are built in a layer-by-layer fashion in the laser powder bed fusion process. Each layer of scan in the parts is defined by a scan strategy that consists of many small patches and scans. The scan length of those multiple scans is not always long enough to have reached a quasi-steady state of the melt pool. The length at which it achieves a steady state is different for different process parameters. The available literature related to the melt pool considers the melt pool has already achieved a steady state, which holds true to a large extent. However, there is always a transient state of melt pool with different characteristics compared to the quasi-steady state. The transient state of the melt pool is particularly significant for small features and thin walls. This paper explores the cross-section and width of the melt track in the transient state. Single-tracks are deposited on semi-cylindrical samples with Ti-6Al-4V powder particles for three levels of power and speed combinations. The single tracks are built at a certain height from the base plate instead of on the build plate to include the effect of the powder particles. The experiment includes single tracks of four scan lengths i.e. 0.25, 0.5, 1 and 2 mm. Once the parts are built and removed from the build plate, White light interferometer is used to capture the melt track information and data processing is done in Matlab™. The results show that the transient length is directly proportional to the laser power and inversely proportional to the scan speed. The highest transient length value is obtained for the highest power of 195 W and lowest scan speed of 50 mm/s.

scholarly journals A new approach for automated measuring of the melt pool geometry in laser-powder bed fusion

2021 ◽  
Author(s):  
Simon Schmid ◽  
Johannes Krabusch ◽  
Thomas Schromm ◽  
Shi Jieqing ◽  
Stefan Ziegelmeier ◽  
...  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Energy Input ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
New Approach ◽  
Powder Bed ◽  
Part Quality ◽  
Melt Pool ◽  
Process Disturbances

AbstractAdditive manufacturing (AM) offers unique possibilities in comparison to conventional manufacturing processes. For example, complex parts can be manufactured without tools. For metals, the most commonly used AM process is laser-powder bed fusion (L-PBF). The L-PBF process is prone to process disturbances, hence maintaining a consistent part quality remains an important subject within current research. An established indicator for quantifying process changes is the dimension of melt pools, which depends on the energy input and the cooling conditions. The melt pool geometry is normally measured manually in cross sections of solidified welding seams. This paper introduces a new approach for the automated visual measuring of melt pools in cross-sections of parts manufactured by L-PBF. The melt pools are first segmented in the images and are then measured. Since the melt pools have a heterogeneous appearance, segmentation with common digital image processing is difficult, deep learning was applied in this project. With the presented approach, the melt pools can be measured over the whole cross section of the specimen. Furthermore, remelted melt pools, which are only partly visible, are evaluated. With this automated approach, a high number of melt pools in each cross-section can be measured, which allows the examination of trends over the build direction in a specimen and results in better statistics. Furthermore, deviations in the energy input can be estimated via the measured melt pool dimensions.

scholarly journals Role of laser powder bed fusion process parameters in crystallographic texture of additive manufactured Nb-48Ti alloy

2021 ◽  
Author(s):  
Rafael de Moura Nobre ◽  
Willy Ank de Morais ◽  
Matheus Tavares Vasques ◽  
Jhoan Guzmán ◽  
Daniel Luiz Rodrigues Junior ◽  
...  
Keyword(s):  
Process Parameters ◽  
Crystallographic Texture ◽  
Fusion Process ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Powder Bed
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