Ab-initio Predictions of Interfacial Heat Flows during the High Speed Casting of Liquid Metals in Near Net Shape Casting Operations

2010 ◽  
Vol 81 (10) ◽  
pp. 891-898 ◽  
Author(s):  
R.I.L. Guthrie ◽  
M. Isac ◽  
D. Li
Keyword(s):  
Ab Initio ◽  
High Speed ◽  
Liquid Metals ◽  
Heat Flows ◽  
Near Net Shape ◽  
High Speed Casting

Hardening of Selective Laser Melted M2 Steel

2021 ◽  
Author(s):  
Mei Yang ◽  
Yishu Zhang ◽  
Haoxing You ◽  
Richard Smith ◽  
Richard D. Sisson
Keyword(s):  
Heat Treatment ◽  
High Speed ◽  
Cutting Tools ◽  
High Speed Steel ◽  
High Hardness ◽  
Steel Part ◽  
X Ray Diffraction ◽  
X Ray ◽  
Heat Treated ◽  
Near Net Shape

Abstract Selective laser melting (SLM) is an additive manufacturing technique that can be used to make the near-net-shape metal parts. M2 is a high-speed steel widely used in cutting tools, which is due to its high hardness of this steel. Conventionally, the hardening heat treatment process, including quenching and tempering, is conducted to achieve the high hardness for M2 wrought parts. It was debated if the hardening is needed for additively manufactured M2 parts. In the present work, the M2 steel part is fabricated by SLM. It is found that the hardness of as-fabricated M2 SLM parts is much lower than the hardened M2 wrought parts. The characterization was conducted including X-ray diffraction (XRD), optical microscopy, Scanning Electron Microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS) to investigate the microstructure evolution of as-fabricated, quenched, and tempered M2 SLM part. The M2 wrought part was heat-treated simultaneously with the SLM part for comparison. It was found the hardness of M2 SLM part after heat treatment is increased and comparable to the wrought part. Both quenched and tempered M2 SLM and wrought parts have the same microstructure, while the size of the carbides in the wrought part is larger than that in the SLM part.

Anwendungszentrum für additive Fertigung/Center for Applied Additive Manufacturing – Influence of process parameters during high-speed laser direct energy deposition

2021 ◽  
Vol 111 (06) ◽  
pp. 368-371
Author(s):  
Sebastian Greco ◽  
Marc Schmidt ◽  
Benjamin Kirsch ◽  
Jan C. Aurich
Keyword(s):  
Additive Manufacturing ◽  
High Speed ◽  
Energy Deposition ◽  
Influence Of Process Parameters ◽  
Direct Energy Deposition ◽  
Additive Fertigung ◽  
Powder Bed ◽  
High Productivity ◽  
Direct Energy ◽  
Near Net Shape

Additive Fertigungsverfahren zeichnen sich durch die Möglichkeit der endkonturnahen Fertigung komplexer Geometrien aus. Die geringe Produktivität etablierter Verfahren wie etwa dem Pulverbettverfahren hemmen aktuell den wirtschaftlichen Einsatz additiver Fertigung. Das Hochgeschwindigkeits-Laserauftragschweißen (HLA) soll durch deutlich erhöhte Auftragsraten und somit bisher unerreicht hoher Produktivität bei der additiven Fertigung dazu beitragen, deren Wirtschaftlichkeit zu steigern.   Additive manufacturing enables the near-net-shape production of complex geometries. The low productivity of established processes such as powder bed processes is currently limiting the economic use of additive manufacturing. High-speed laser direct energy deposition (HS LDED) is expected to improve the economic efficiency of additive manufacturing by significantly increasing deposition rates and thus previously unattained high productivity.

scholarly journals Characterization of Ultrasonic Bubble Clouds in A Liquid Metal by Synchrotron X-ray High Speed Imaging and Statistical Analysis

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 44 ◽  
Author(s):  
Chuangnan Wang ◽  
Thomas Connolley ◽  
Iakovos Tzanakis ◽  
Dmitry Eskin ◽  
Jiawei Mi
Keyword(s):  
High Speed ◽  
Liquid Metals ◽  
Quantitative Information ◽  
Ultrasonic Waves ◽  
High Speed Imaging ◽  
X Ray ◽  
Processing Strategies ◽  
Solidification Processes ◽  
Bubble Clouds ◽  
Temperature Liquid

Quantitative understanding of the interactions of ultrasonic waves with liquid and solidifying metals is essential for developing optimal processing strategies for ultrasound processing of metal alloys in the solidification processes. In this research, we used the synchrotron X-ray high-speed imaging facility at Beamline I12 of the Diamond Light Source, UK to study the dynamics of ultrasonic bubbles in a liquid Sn-30wt%Cu alloy. A new method based on the X-ray attenuation for a white X-ray beam was developed to extract quantitative information about the bubble clouds in the chaotic and quasi-static cavitation regions. Statistical analyses were made on the bubble size distribution, and velocity distribution. Such rich statistical data provide more quantitative information about the characteristics of ultrasonic bubble clouds and cavitation in opaque, high-temperature liquid metals.

scholarly journals Spatially Resolved Velocity Mapping of the Melt Plume During High-Pressure Gas Atomization of Liquid Metals

2020 ◽  
Vol 51 (5) ◽  
pp. 1973-1988
Author(s):  
T. D. Bigg ◽  
A. M. Mullis
Keyword(s):  
High Pressure ◽  
High Speed ◽  
Average Velocity ◽  
Liquid Metals ◽  
Gas Atomization ◽  
Velocity Mapping ◽  
Analysis Algorithm ◽  
Spatially Resolved ◽  
Image Analysis Algorithm ◽  
The Many

Abstract We present details of an image analysis algorithm designed specifically to determine the velocity of material in the melt plume during high-pressure, close-coupled gas atomization. Following high-speed filming (16,000 fps) pairs of images are used to identify and track dominant features within the plume. Due to the complexity of the atomization plume, relatively few features are tracked between any given pair of images, but by averaging over the many thousands of frames obtained during high-speed filming a spatially resolved map of the average velocity of material in the plume can be built up. Velocities in the plume are typically very low compared to that of the supersonic gas, being around 30 m s−1 on the margins of the plume where the melt interacts strongly with the gas and dropping to < 10 m s−1 in the center of the melt plume. Consequently, the efficiency of the atomizer in transferring kinetic energy from the gas to the melt is correspondingly very low, with this being estimated as being no more than 0.1 pct.

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