Experimental analysis of the influence of process parameters on the melt pool formation and stability in powder bed laser

2013 ◽  
Author(s):  
Runchen Cao ◽  
Pascal Aubry ◽  
Kevin Verdier
Keyword(s):  
Process Parameters ◽  
Experimental Analysis ◽  
Influence Of Process Parameters ◽  
Powder Bed ◽  
Melt Pool ◽  
Pool Formation

scholarly journals The effects of locations on the build tray on the quality of specimens in powder bed additive manufacturing

2021 ◽  
Author(s):  
Snehashis Pal ◽  
Nenad Gubeljak ◽  
Tonica Bončina ◽  
Radovan Hudák ◽  
Teodor Toth ◽  
...  
Keyword(s):  
Main Role ◽  
Particle Sizes ◽  
Additional Experiment ◽  
Powder Bed ◽  
Melt Pool ◽  
Start Line ◽  
Sample Density ◽  
Powder Layering ◽  
Pool Formation

AbstractIn this study, the effect of powder spreading direction was investigated on selectively laser-melted specimens. The results showed that the metallurgical properties of the specimens varied during fabrication with respect to their position on the build tray. The density, porosity, and tensile properties of the Co–Cr–W–Mo alloy were investigated on cuboid and tensile specimens fabricated at different locations. Two different significant positions on the tray were selected along the powder spreading direction. One set of specimens was located near the start line of powder spreading, and the other set was located near the end of the building tray. The main role in the consequences of powder layering was played by the distribution of powder particle sizes and the packing density of the layers. As a result, laser penetration, melt pool formation, and fusion characteristics varied. To confirm the occurrence of variations in sample density, an additional experiment was performed with a Ti–6Al–4V alloy. Furthermore, the powders were collected at two different fabricating locations and their size distribution for both materials was investigated.

scholarly journals A Melt Pool Temperature Model in Laser Powder Bed Fabricated CM247LC Ni Superalloy to Rationalize Crack Formation and Microstructural Inhomogeneities

2021 ◽  
Author(s):  
Di Wang ◽  
Sheng Li ◽  
Guowei Deng ◽  
Yang Liu ◽  
Moataz M. Attallah
Keyword(s):  
Energy Density ◽  
Process Parameters ◽  
Crack Formation ◽  
Crack Density ◽  
Chemical Compositions ◽  
Temperature Model ◽  
Powder Bed ◽  
Melt Pool ◽  
Melt Pool Temperature ◽  
The Impact

AbstractThis study of the laser powder bed fusion (LPBF) of γ′-strengthened Ni superalloy CM247LC focuses on the development of a melt pool temperature model to predict crack density within the alloy. This study also analyzes spatter and elemental evaporation, which might cause defects and inhomogeneities, at different melt pool temperatures. The melt pool temperature model provides more accurate predictions than the widely used energy density model. Spatter particles were collected and characterized to study their sizes and chemical compositions, compared with the virgin powder, recycled powder, and as-built samples, to probe the impact of their entrapment into the melt pool. This study also investigated Al evaporation, revealing that its extent does not correlate with the laser energy density and is believed to be rather limited by comparing the chemistry of the virgin powder and the build. Last, the impact of LPBF process parameters on the formation of these inhomogeneities, and accordingly crack formation, was studied using finite element analysis by estimating the maximum melt pool temperature and correlating it with the formation of the microstructural inhomogeneities. The morphology of the various cracking modes was associated with the process parameters.

scholarly journals The Influence of Process Parameters and Build Orientation on the Creep Behaviour of a Laser Powder Bed Fused Ni-based Superalloy for Aerospace Applications

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1390 ◽  
Author(s):  
Hani Hilal ◽  
Robert Lancaster ◽  
Spencer Jeffs ◽  
John Boswell ◽  
David Stapleton ◽  
...  
Keyword(s):  
Process Parameters ◽  
Structural Integrity ◽  
Mechanical Performance ◽  
Creep Behaviour ◽  
Test Method ◽  
Influence Of Process Parameters ◽  
Powder Bed ◽  
Build Orientation ◽  
Aerospace Applications ◽  
Layer Manufacturing

Additive Layer Manufacturing (ALM) is an innovative net shape manufacturing technology that offers the ability to produce highly intricate components not possible through traditional wrought and cast procedures. Consequently, the aerospace industry is becoming ever more attentive in exploiting such technology for the fabrication of nickel-based superalloys in an attempt to drive further advancements within the holistic gas turbine. Given this, the requirement for the mechanical characterisation of such material is rising in parallel, with limitations in the availability of material processed restricting conventional mechanical testing; particularly with the abundance of process parameters to evaluate. As such, the Small Punch Creep (SPC) test method has been deemed an effective tool to rank the elevated temperature performance of alloys processed through ALM, credited to the small volumes of material utilised in each test and the ability to sample material from discrete locations. In this research, the SPC test will be used to assess the influence of a number of key process variables on the mechanical performance of Laser Powder Bed Fused (LPBF) Ni-based superalloy CM247LC. This will also include an investigation into the influence of build orientation and post-build treatment on creep performance, whilst considering the structural integrity of the different experimental builds.

scholarly journals Influence of Melt-Pool Stability in 3D Printing of NdFeB Magnets on Density and Magnetic Properties

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 139 ◽  
Author(s):  
Mateusz Skalon ◽  
Michael Görtler ◽  
Benjamin Meier ◽  
Siegfried Arneitz ◽  
Nikolaus Urban ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Layer Thickness ◽  
Process Parameters ◽  
Permanent Magnets ◽  
Scanning Speed ◽  
Maximum Energy ◽  
Powder Layer ◽  
Influence Of Process Parameters ◽  
Layer Height ◽  
Melt Pool

The current work presents the results of an investigation focused on the influence of process parameters on the melt-track stability and its consequence to the sample density printed out of NdFeB powder. Commercially available powder of Nd7.5Pr0.7Fe75.4Co2.5B8.8Zr2.6Ti2.5 alloy was investigated at the angle of application in selective laser melting of permanent magnets. Using single track printing the stability of the melt pool was investigated under changing process parameters. The influence of changing laser power, scanning speed, and powder layer thickness on density, porosity structure, microstructure, phase composition, and magnetic properties were investigated. The results showed that energy density coupled with powder layer thickness plays a crucial role in melt-track stability. It was possible to manufacture magnets of both high relative density and high magnetic properties. Magnetization tests showed a significant correlation between the shape of the demagnetization curve and the layer height. While small layer heights are beneficial for sufficient magnetic properties, the remaining main parameters tend to affect the magnetic properties less. A quasi-linear correlation between the layer height and the magnetic properties remanence (Jr), coercivity (HcJ) and maximum energy product ((BH)max) was found.

scholarly journals Laser powder bed fusion of AA7075 alloy: Influence of process parameters on porosity and hot cracking

2020 ◽  
Vol 35 ◽  
pp. 101270 ◽  
Author(s):  
Wojciech Stopyra ◽  
Konrad Gruber ◽  
Irina Smolina ◽  
Tomasz Kurzynowski ◽  
Bogumiła Kuźnicka
Keyword(s):  
Process Parameters ◽  
Hot Cracking ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Influence Of Process Parameters ◽  
Powder Bed

scholarly journals Evaluation of spatter particles, metal vapour jets, and depressions considering influence of laser incident angle on melt pool behaviour

2021 ◽  
Author(s):  
Kotaro Tsubouchi ◽  
Tatsuaki Furumoto ◽  
Mitsugu Yamaguchi ◽  
Atsushi Ezura ◽  
Shinnosuke Yamada ◽  
...  
Keyword(s):  
Laser Beam ◽  
High Speed ◽  
Incident Angle ◽  
Three Dimensional ◽  
Burial Depth ◽  
Metal Vapour ◽  
Building Conditions ◽  
Powder Bed ◽  
Melt Pool ◽  
Pool Formation

Abstract Building of practical parts involves the application of metal-based laser powder bed fusion using a laser beam (PBF-LB/M) owing to its high-precision manufacturing. However, the quality of the built parts obtained via the PBF-LB/M processes varies with the building conditions, and a thorough understanding of the building mechanism has not been achieved owing to the complex and interrelated process parameters involved. The incident angle of the laser beam, which changes on the platform during the laser beam scan owing to the designed three-dimensional data, is among the principal parameters that affects the building aspects. In this study, the melt pool in the singletrack formation during the PBF-LB/M processes was visualised using a high-speed camera, and the influence of the laser incident angle on the ejection characteristics of spatter particles formed around the laser-irradiated area was investigated. Consequently, the spatter particles and metal vapour jet behaviour varied with the laser incident angle. There was a reduction in number of spatter particles owing to the origin of the incident direction being from behind the laser irradiation area. In addition, the laser incident angle also affected the melt pool morphology because of the depression in the melting. Furthermore, the burial depth of the pores varied with the laser incident angle, and is related to the depth of the depression during the melt pool formation.

scholarly journals A Review on Melt-Pool Characteristics in Laser Welding of Metals

2018 ◽  
Vol 2018 ◽  
pp. 1-18 ◽  
Author(s):  
Behzad Fotovvati ◽  
Steven F. Wayne ◽  
Gladius Lewis ◽  
Ebrahim Asadi
Keyword(s):  
Laser Welding ◽  
Process Parameters ◽  
Welding Process ◽  
Review Of The Literature ◽  
Influence Of Process Parameters ◽  
Melt Pool ◽  
Modeling Studies ◽  
Melt Pool Characteristics ◽  
Validation Of Results ◽  
Metal Additive

Laser welding of metals involves with formation of a melt-pool and subsequent rapid solidification, resulting in alteration of properties and the microstructure of the welded metal. Understanding and predicting relationships between laser welding process parameters, such as laser speed and welding power, and melt-pool characteristics have been the subjects of many studies in literature because this knowledge is critical to controlling and improving laser welding. Recent advances in metal additive manufacturing processes have renewed interest in the melt-pool studies because in many of these processes, part fabrication involves small moving melt-pools. The present work is a critical review of the literature on experimental and modeling studies on laser welding, with the focus being on the influence of process parameters on geometry, thermodynamics, fluid dynamics, microstructure, and porosity characteristics of the melt-pool. These data may inform future experimental laser welding studies and may be used for verification and validation of results obtained in future melt-pool modeling studies.

scholarly journals Formation processes for large ejecta and interactions with melt pool formation in powder bed fusion additive manufacturing

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Abdalla R. Nassar ◽  
Molly A. Gundermann ◽  
Edward W. Reutzel ◽  
Paul Guerrier ◽  
Michael H. Krane ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Formation Processes ◽  
Powder Bed Fusion ◽  
Powder Bed ◽  
Melt Pool ◽  
Pool Formation
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