Carbon Particle In-Situ Alloying of the Case-Hardening Steel 16MnCr5 in Laser Powder Bed Fusion

The carbon content of steel affects many of its essential properties, e.g., hardness and mechanical strength. In the powder bed fusion process of metals using a laser beam (PBF-LB/M), usually, pre-alloyed metal powder is solidified layer-by-layer using a laser beam to create parts. A reduction of the carbon content in steels is observed during this process. This study examines adding carbon particles to the metal powder and in situ alloying in the PBF-LB/M process as a countermeasure. Suitable carbon particles are selected and their effect on the particle size distribution and homogeneity of the mixtures is analysed. The workability in PBF-LB is then shown. This is followed by an evaluation of the resulting mechanical properties (hardness and mechanical strength) and microstructure in the as-built state and the state after heat treatment. Furthermore, potential use cases like multi-material or functionally graded parts are discussed.

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In-situ measurement and monitoring methods for metal powder bed fusion – an updated review

Measurement Science and Technology ◽

10.1088/1361-6501/ac0b6b ◽

2021 ◽

Author(s):

Marco Luigi Giuseppe Grasso ◽

Afaf Remani ◽

Andrew Dickins ◽

B M Colosimo ◽

Richard K Leach

Keyword(s):

Metal Powder ◽

In Situ Measurement ◽

Powder Bed Fusion ◽

Monitoring Methods ◽

Powder Bed

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Experimental and Numerical Investigations of In Situ Alloying during Powder Bed Fusion of Metals Using a Laser Beam

Metals ◽

10.3390/met11111842 ◽

2021 ◽

Vol 11 (11) ◽

pp. 1842

Author(s):

Andreas Wimmer ◽

Baturay Yalvac ◽

Christopher Zoeller ◽

Fabian Hofstaetter ◽

Stefan Adami ◽

...

Keyword(s):

Laser Beam ◽

Powder Bed Fusion ◽

Stainless Steel 316L ◽

Powder Bed ◽

Industrial Sectors ◽

Numerical Studies ◽

Future Success ◽

Particle Hydrodynamics ◽

Smoothed Particle

Powder Bed Fusion of Metals using a Laser Beam (PBF-LB/M) is increasingly utilized for the fabrication of complex parts in various industrial sectors. Enabling a robust and reproducible manufacturing process is one of the main goals in view of the future success of PBF-LB/M. To meet these challenges, alloys that are specifically adapted to the process are required. This paper demonstrates the successful interplay of simulation studies with experimental data to analyze the basic phenomena of in situ alloying. The meshless Smoothed-Particle Hydrodynamics (SPH) method was employed for the numerical simulation of two-component powder systems considering both thermodynamics and fluid mechanics in the solid and the melt phase. The simulation results for the in situ alloying of stainless steel 316L blended with the aluminum alloy AlSi10Mg were enriched and validated with the data from a novel experimental test bench. The combination of both approaches can enhance the understanding of the process for in situ alloying. Therefore, future investigations of the PBF-LB/M process with multi-component powder systems can benefit from detailed numerical studies using SPH.

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Influence of Part Geometry and Feature Size on the Resulting Microstructure and Mechanical Properties of the Case Hardening Steel 16MnCr5 processed by Laser Powder Bed Fusion

Procedia CIRP ◽

10.1016/j.procir.2021.11.122 ◽

2021 ◽

Vol 104 ◽

pp. 726-731

Author(s):

Matthias Schmitt ◽

Florian Gerstl ◽

Max Boesele ◽

Max Horn ◽

Georg Schlick ◽

...

Keyword(s):

Mechanical Properties ◽

Case Hardening ◽

Powder Bed Fusion ◽

Laser Powder Bed Fusion ◽

Feature Size ◽

Powder Bed ◽

Part Geometry ◽

Microstructure And Mechanical Properties ◽

Case Hardening Steel

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Influence of Support Structures on the Microstructure and Mechanical Properties of Case Hardening Steel in Laser Powder Bed Fusion

SSRN Electronic Journal ◽

10.2139/ssrn.3724368 ◽

2020 ◽

Author(s):

Matthias Schmitt ◽

Maximilian Bösele ◽

Georg Schlick ◽

Gunther Reinhart

Keyword(s):

Mechanical Properties ◽

Case Hardening ◽

Powder Bed Fusion ◽

Support Structures ◽

Laser Powder Bed Fusion ◽

Powder Bed ◽

Microstructure And Mechanical Properties ◽

Case Hardening Steel

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Influence of Intrinsic Heat Treatment (IHT) on Precipitation Kinetics during Laser Beam Powder Bed Fusion of Al-Mg-Sc Alloy

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1161.47 ◽

2021 ◽

Vol 1161 ◽

pp. 47-55

Author(s):

Yuvaraj Ganpati Patil ◽

Loreen Mertens ◽

Andre Dröse ◽

Vasily Ploshikhin

Keyword(s):

Laser Beam ◽

Volume Fraction ◽

Rapid Heating ◽

Process Analysis ◽

Powder Bed Fusion ◽

Precipitation Kinetics ◽

Powder Bed ◽

Post Process ◽

Heating And Cooling

Laser Beam Powder Bed Fusion (LBPBF) process has a unique feature termed as IntrinsicHeat Treatment (IHT), where solidified layers undergo series of heating and cooling (during thesubsequent building of a part). Thus, the LBPBF process offers the opportunity for the formation of microstructuralfeatures, which can have the potential to transform the mechanical properties of the part.In the case of AlMgSc alloy, L12 phase Al3Sc precipitates are thermodynamically favored to nucleatein the Al matrix due to coherency. After post-process analysis, it is evident that Al3Sc precipitatesformed during the LBPBF process, but it is unlikely to monitor (in-situ) the kinetics of precipitation.Therefore, based on inputs from the thermal model, the simulation of precipitation kinetics during theLBPBF process (IHT) is performed. The rapid heating and cooling cause the formation of new vacancies,where Al3Sc precipitates can nucleate and grow. The KWN model based on solid-state phasetransformation is used for modeling of precipitation kinetics. The thermal data at two locations in apart is collected and used to determine the average radius, number density, and volume fraction ofprecipitates. It is found that the IHT does not influence precipitation kinetics, and has no potential toalter the spatial properties of the part.

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Finite Element Analysis of Interaction of Laser Beam with Material in Laser Metal Powder Bed Fusion Process

Materials ◽

10.3390/ma11050765 ◽

2018 ◽

Vol 11 (5) ◽

pp. 765 ◽

Cited By ~ 7

Author(s):

Guang Fu ◽

David Zhang ◽

Allen He ◽

Zhongfa Mao ◽

Kaifei Zhang

Keyword(s):

Finite Element Analysis ◽

Finite Element ◽

Laser Beam ◽

Metal Powder ◽

Fusion Process ◽

Powder Bed Fusion ◽

Element Analysis ◽

Powder Bed

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In situ alloying: investigation of the melt pool stability during powder bed fusion of metals using a laser beam in a novel experimental set-up

Progress in Additive Manufacturing ◽

10.1007/s40964-021-00233-y ◽

2021 ◽

Author(s):

Andreas Wimmer ◽

Fabian Hofstaetter ◽

Constantin Jugert ◽

Katrin Wudy ◽

Michael F. Zaeh

Keyword(s):

Laser Beam ◽

High Speed ◽

Process Zone ◽

Powder Bed Fusion ◽

Powder Bed ◽

Limited Access ◽

Pool Depth ◽

Melt Pool ◽

Melt Pool Characteristics

AbstractThe limited access to materials for the Powder Bed Fusion of Metals using a Laser Beam (PBF-LB/M) is compensated by in situ alloying. Individual melt pool characteristics can be specifically influenced to improve the mechanical properties of the final part. However, conventional PBF-LB/M machines allow only limited access for detailed observation of the process zone and, in particular, the melt pool. This paper presents a methodology for systematically analyzing the melt pool in the cross section to determine the in situ variation of the melt pool depth. A custom PBF-LB/M test bench was devised to enable investigation of the process zone using high-speed infrared cameras. The image data were processed automatically using a dedicated algorithm. The methodology was applied to analyze the effect of additives on the melt pool stability. Stainless steel 316L powder was blended with the aluminum alloy AlSi10Mg by up to 20 wt.%. It was found that the blended powder significantly reduced the variation of the melt pool depth.

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