Atomization mechanism and powder morphology in laminar flow gas atomization

Hybrid atomization is a new atomization technique that combines gas atomization with centrifugal atomization. This process can produce fine, spherical powders economically with a mean size of about 10 μm diameter and a tight size distribution. Experiments on the process were carried out using a Sn-9 mass% Zn alloy to investigate the influence of processing parameters on powder characteristics in hybrid atomization. The primary atomization mechanism under normal hybrid atomization conditions is predicted to be direct drop formation mode.

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Solidification Characterization of K418 Alloy Powders Fabricated by Argon Gas Atomization

Materials Science Forum ◽

10.4028/www.scientific.net/msf.849.788 ◽

2016 ◽

Vol 849 ◽

pp. 788-793 ◽

Cited By ~ 1

Author(s):

Liang Liang Lu ◽

Shao Ming Zhang ◽

Jun Xu ◽

Yan Wei Sheng ◽

Shan Shan Wang ◽

...

Keyword(s):

Particle Size ◽

Cooling Rate ◽

Particle Surface ◽

Spherical Shape ◽

Solidification Process ◽

Average Diameter ◽

Powder Particle Size ◽

Gas Atomization ◽

Powder Morphology

The solidification characterization of K418 alloy powders prepared by argon atomization was studied, and thermal parameters of the alloy powder during solidification process were calculated. The results show that powder morphology is spherical shape, the average diameter of the powder is 55μm, the amount of less 100μm powder is about 90 percent, the solidification microstructure of powders particle surface are dentrite and cellular structure. Decreasing the particle size, the microstructures of particle interior change from dentrite in major to cellular structures, and the structure is more uniformed. The length of secondary dentritic arm and the cooling rate as a function of K418 alloy powders size is established, the cooling rate increases with a decrease of the powder particle size, the cooling rate is in the range of 104K.S-1-106K.S-1.

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Research of 316L Metallic Powder for Use in SLM 3D Printing

Advances in Materials Science ◽

10.2478/adms-2020-0001 ◽

2020 ◽

Vol 20 (1) ◽

pp. 5-15 ◽

Cited By ~ 2

Author(s):

J. Hajnys ◽

M. Pagac ◽

J. Mesicek ◽

J. Petru ◽

F. Spalek

Keyword(s):

Size Fraction ◽

Quantitative Result ◽

Accurate Method ◽

Metallic Powder ◽

Gas Atomization ◽

Small Particles ◽

Powder Morphology ◽

Metal Printing ◽

Input Material ◽

3D Metal Printing

Abstract3D metal printing is an increasingly popular production of steel parts. The most widespread and most accurate method is SLM (Selective Laser Melting), which uses metallic powder as the input material. The article is dedicated to researching the supplied powder from Renishaw. The powder is made by gas atomization and 3 phases of powder (virgin, sift and waste) that are present in the SLM process are examined. Powder morphology by SEM electron microscopy is investigated and the porosity of the powder is measured by optical method. Next, the powder grain size fraction is examined. In conclusion, there are recommendations and other directions of possible research. The main quantitative result from research is that, in general, small particles are reduced in the sift powder and the number of larger particles is increased, but the powder is still usable for further use.

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A TEM study of the effect of oxygen on nanocavity formation and precipitation in rapid - solidified Fe-16Ni-9Cr stainless steels

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100171237 ◽

1994 ◽

Vol 52 ◽

pp. 700-701

Author(s):

S. Wisutmethangoon ◽

T. F. Kelly ◽

J.E. Flinn

Keyword(s):

Stainless Steels ◽

High Mobility ◽

Hot Extrusion ◽

Extrusion Ratio ◽

Gas Atomization ◽

Cavity Formation ◽

Nucleation Sites ◽

Heat Treated ◽

Different Types ◽

Effect Of Oxygen

Vacancies are introduced into the crystal phase during quenching of rapid solidified materials. Cavity formation occurs because of the coalescence of the vacancies into a cluster. However, because of the high mobility of vacancies at high temperature, most of them will diffuse back into the liquid phase, and some will be lost to defects such as dislocations. Oxygen is known to stabilize cavities by decreasing the surface energy through a chemisorption process. These stabilized cavities, furthermore, act as effective nucleation sites for precipitates to form during aging. Four different types of powders with different oxygen contents were prepared by gas atomization processing. The atomized powders were then consolidated by hot extrusion at 900 °C with an extrusion ratio 10,5:1. After consolidation, specimens were heat treated at 1000 °C for 1 hr followed by water quenching. Finally, the specimens were aged at 600 °C for about 800 hrs. TEM samples were prepared from the gripends of tensile specimens of both unaged and aged alloys.

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