scholarly journals DC Arc Plasma Treatment for Defect Reduction in WC-Co Granulated Powder

Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 975
Author(s):  
Hirotomo Itagaki ◽  
Taisei Yachi ◽  
Hisato Ogiso ◽  
Harumichi Sato ◽  
Yorihiro Yamashita ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Plasma Treatment ◽  
Spray Coating ◽  
Xrd Analysis ◽  
Arc Plasma ◽  
Defect Reduction ◽  
Spherical Powder ◽  
Powder Particles ◽  
Residual Strains ◽  
Dc Arc

Tungsten carbide–cobalt (WC–Co) agglomerated powder is widely used for additive manufacturing and spray coating, and a reduction in internal gaps in the powder is required to obtain a product of high quality. In this paper, we investigate plasma effects on agglomerated powder when WC–12%Co powder is directly subjected to direct current (DC) arc plasma treatment to reduce gaps in the WC–Co powder. We obtain a plasma-treated powder with reduced gaps among WC particles. Furthermore, plasma-treatment improves the sphericity of the powder particles, due to the spheroidization effect, so that the percentage of plasma-treated particles exceeding 95% sphericity is 50%, which is 1.7 times that of raw powder. Concern regarding the possible generation of W2C by plasma treatment is unfounded, with W2C levels kept very low according to X-ray diffraction (XRD) analysis, showing a value of 0.0075 for the area ratio W2C(002)/WC(100). XRD analysis also reveals that plasma treatment relaxes residual strains in the powder. From these results, the DC plasma treatment of WC agglomerated powder produces a spherical powder with fewer gaps and strains in the powder, making it more suitable for additive manufacturing while suppressing decarburization.

Non-Equilibrium Nitrogen DC-Arc Plasma Treatment of TiO2 Nanopowder

2009 ◽  
Vol 9 (1) ◽  
pp. 256-260 ◽  
Author(s):  
Yoshikazu Suzuki ◽  
José Gonzalez-Aguilar ◽  
Noel Traisnel ◽  
Marie-Hélène Berger ◽  
Monique Repoux ◽  
...  
Keyword(s):  
Plasma Treatment ◽  
Arc Plasma ◽  
Dc Arc ◽  
Non Equilibrium

MOTION OF ANODE ATTACHMENT AND FLUCTUATIONS OF PLASMA JET IN DC ARC PLASMA TORCH

1997 ◽  
Vol 1 (2) ◽  
pp. 167-178 ◽  
Author(s):  
Milan Hrabovsky ◽  
M. Konrad ◽  
Vladimir Kopecky ◽  
J. Hlina ◽  
J. Benes ◽  
...  
Keyword(s):  
Plasma Torch ◽  
Plasma Jet ◽  
Arc Plasma ◽  
Arc Plasma Torch ◽  
Dc Arc ◽  
Dc Arc Plasma Torch

scholarly journals Phase-field modeling of grain evolutions in additive manufacturing from nucleation, growth, to coarsening

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Min Yang ◽  
Lu Wang ◽  
Wentao Yan
Keyword(s):  
Additive Manufacturing ◽  
Phase Field ◽  
Field Model ◽  
Three Dimensional ◽  
Phase Field Model ◽  
Nucleation Theory ◽  
Experimental Result ◽  
Classical Nucleation Theory ◽  
Validation Experiment ◽  
Powder Particles

AbstractA three-dimensional phase-field model is developed to simulate grain evolutions during powder-bed-fusion (PBF) additive manufacturing, while the physically-informed temperature profile is implemented from a thermal-fluid flow model. The phase-field model incorporates a nucleation model based on classical nucleation theory, as well as the initial grain structures of powder particles and substrate. The grain evolutions during the three-layer three-track PBF process are comprehensively reproduced, including grain nucleation and growth in molten pools, epitaxial growth from powder particles, substrate and previous tracks, grain re-melting and re-growth in overlapping zones, and grain coarsening in heat-affected zones. A validation experiment has been carried out, showing that the simulation results are consistent with the experimental results in the molten pool and grain morphologies. Furthermore, the grain refinement by adding nanoparticles is preliminarily reproduced and compared against the experimental result in literature.

Integrated purification of Gd and preparation of Gd2O3 nanoparticles by DC arc plasma*

2021 ◽  
Author(s):  
Zhenggang Tang ◽  
Minjie Hou ◽  
Xin He ◽  
Kai Ye ◽  
Da Zhang ◽  
...  
Keyword(s):  
Arc Plasma ◽  
Gd2o3 Nanoparticles ◽  
Dc Arc

Plasma Treatment of Polyethylene Powder Particles in a Hollow Cathode Glow Discharge

2009 ◽  
Vol 6 (S1) ◽  
pp. S392-S396 ◽  
Author(s):  
Meike Quitzau ◽  
Matthias Wolter ◽  
Holger Kersten
Keyword(s):  
Glow Discharge ◽  
Plasma Treatment ◽  
Hollow Cathode ◽  
Powder Particles ◽  
Polyethylene Powder

scholarly journals Processing of Al2O3-AlN Ceramics and Their Structural, Mechanical, and Tribological Characterization

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6055
Author(s):  
Dheeraj Varanasi ◽  
Monika Furkó ◽  
Katalin Balázsi ◽  
Csaba Balázsi
Keyword(s):  
Mechanical Properties ◽  
Aluminum Nitride ◽  
Hot Isostatic Pressing ◽  
Xrd Analysis ◽  
Mechanical Tests ◽  
Oxidation Time ◽  
Bending Test ◽  
Coarse Powder ◽  
Powder Particles ◽  
Tribological Characterization

The aim of this study is to present a novel, lower sintering temperature preparation, processing, structural, mechanical, and tribological testing of the AlN-Al2O3 ceramics. The precursor powder of AlN was subjected to oxidation in ambient environment at 900 °C for 3, 10, and 20 h, respectively. These oxidized powders were characterized by SEM and XRD to reveal their morphology, phase, and crystal structure. The SEM results showed coarse powder particles and the presence of aluminum oxide (Al2O3) phase at the surface of aluminum nitride (AlN). The XRD analysis has shown increasing aluminum-oxy-nitride conversion of aluminum nitride as the holding time of oxidation increased. The highest percentage of conversion of AlN powder to AlN-Al2O3 was observed after 10 h. Simultaneously the powders were compacted and sintered using the hot isostatic pressing (HIP) under inert environment (N2 gas) at 1700 °C, 20 MPa for 5 h. This led to the compaction and increase in density of the final samples. Mechanical tests, such as bending test and tribology tests, were carried out on the samples. The mechanical properties of the samples were observed to improve in the oxidized samples compared to the precursor AlN. Moreover, applying longer oxidation time, the mechanical properties of the sintered samples enhanced significantly. Optimum qualitative (microstructure, oxide percentage) and quantitative (tribology, hardness, and bending tests) properties were observed in samples with 10-h oxidation time.

Deposition of large area high quality diamond wafers with high growth rate by DC arc plasma jet

2000 ◽  
Vol 9 (9-10) ◽  
pp. 1673-1677 ◽  
Author(s):  
H. Guo ◽  
Z.L. Sun ◽  
Q.Y. He ◽  
S.M. Du ◽  
X.B. Wu ◽  
...  
Keyword(s):  
Growth Rate ◽  
High Growth ◽  
Plasma Jet ◽  
High Growth Rate ◽  
Arc Plasma ◽  
Large Area ◽  
High Quality ◽  
Dc Arc

Fracture behavior of diamond films deposited by DC arc plasma jet CVD

2018 ◽  
Vol 44 (11) ◽  
pp. 13402-13408 ◽  
Author(s):  
Kang An ◽  
Liangxian Chen ◽  
Xiongbo Yan ◽  
Xin Jia ◽  
Yun Zhao ◽  
...  
Keyword(s):  
Fracture Behavior ◽  
Diamond Films ◽  
Plasma Jet ◽  
Arc Plasma ◽  
Dc Arc
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