scholarly journals Material Erosion and Dust Formation during Tungsten Exposure to Hollow-Cathode and Microjet Discharges

2020 ◽  
Vol 10 (19) ◽  
pp. 6870
Author(s):  
Valentina Marascu ◽  
Cristian Stancu ◽  
Veronica Satulu ◽  
Anca Bonciu ◽  
Christian Grisolia ◽  
...  
Keyword(s):  
Surface Modification ◽  
High Temperature ◽  
Chemical Composition ◽  
Dust Formation ◽  
Material Damage ◽  
Fusion Technology ◽  
Large Area ◽  
Electrode Surfaces ◽  
Tungsten Electrodes ◽  
Material Erosion

Tungsten erosion and dust occurrence are phenomena of great interest for fusion technology. Herein, we report results concerning the material damage and dust formation in the presence of high temperature and large area or concentrated discharges in helium and argon. In order to generate adequate plasmas, we used tungsten electrodes in two experimental discharge systems, namely a hollow discharge and a microjet discharge. In both exposure cases, we noticed surface modification, which was assigned to sputtering, melting, and vaporization processes, and a significant dust presence. We report the formation on electrode surfaces of tungsten fuzz, nano-cones, nanofibers, and cauliflower- and faced-like particles, depending on the discharge and gas type. Dust with various morphologies and sizes was collected and analyzed with respect to the morphology, size distribution, and chemical composition. We noticed, with respect to erosion and particle formation, common behaviors of W in both laboratory and fusion facilities experiments.

scholarly journals KAJIAN KERUSAKAN MATERIAL SUPERHEATER TUBE 2” DENGAN PENDEKATAN STANDAR ASTM

2008 ◽  
Vol 8 (2) ◽  
pp. 74
Author(s):  
Koos Sardjono Kuntadi
Keyword(s):  
High Temperature ◽  
Chemical Composition ◽  
High Strength ◽  
Composition Analysis ◽  
Material Damage ◽  
Pipe Material ◽  
Warm Up ◽  
Superheater Tube ◽  
Steel Material ◽  
Chemical Composition Analysis

<p>Equipments used in industry process and migas is generally designed from alloy of steel which hold up to high temperature and attack corrosion. Based on that, it’s require to be conducted an material operation and election, like a component Boiler that is Secondary Superheater is generally weared by pipe from alloy of steel material Cr- Mo or steel with Austenitik type.<br />To know the damage of Secondary Superheater tube 2" material, can be conducted by a chemical composition analysis, test inspection metalografi and hardness. The damage of Material Secondary Superheater tube 2" at the extension las elbow in the form of rip on second potition (ASTM SA - 192) representing a militant low strength carbon material pipe, while on the first potition which there are not pipe material damage representing a militant high strength carbon (ASTM SA - 106 grade C) which a different thick each other. Attenuating showed the thick degradation which possible because of local stream turbulensi warm-up existence and which is high enough, this matter is shown with existence</p>

NICROFER 5520 Co

Alloy Digest ◽  
1995 ◽  
Vol 44 (3) ◽  
Keyword(s):  
High Temperature ◽  
Chemical Composition ◽  
Physical Properties ◽  
Tensile Properties ◽  
High Temperatures ◽  
Heat Treating ◽  
High Temperature Corrosion ◽  
Creep Properties ◽  
Nickel Chromium ◽  
Temperature Performance

Abstract NICROFER 5520 Co is a nickel-chromium-cobalt-molybdenum alloy with excellent strength and creep properties up to high temperatures. Due to its balanced chemical composition the alloy shows outstanding resistance to high temperature corrosion in the form of oxidation and carburization. This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on high temperature performance as well as forming, heat treating, machining, and joining. Filing Code: Ni-480. Producer or source: VDM Technologies Corporation.

scholarly journals Surface modification of PMMA polymer and its composites with PC61BM fullerene derivative using an atmospheric pressure microwave argon plasma sheet

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Andrzej Sikora ◽  
Dariusz Czylkowski ◽  
Bartosz Hrycak ◽  
Magdalena Moczała-Dusanowska ◽  
Marcin Łapiński ◽  
...  
Keyword(s):  
Contact Angle ◽  
Surface Modification ◽  
Chemical Composition ◽  
Water Contact Angle ◽  
Plasma Sheet ◽  
Atmospheric Pressure ◽  
Argon Plasma ◽  
Fullerene Derivative ◽  
Water Contact ◽  
Pmma Polymer

AbstractThis paper presents the results of experimental investigations of the plasma surface modification of a poly(methyl methacrylate) (PMMA) polymer and PMMA composites with a [6,6]-phenyl-C61-butyric acid methyl ester fullerene derivative (PC61BM). An atmospheric pressure microwave (2.45 GHz) argon plasma sheet was used. The experimental parameters were: an argon (Ar) flow rate (up to 20 NL/min), microwave power (up to 530 W), number of plasma scans (up to 3) and, the kind of treated material. In order to assess the plasma effect, the possible changes in the wettability, roughness, chemical composition, and mechanical properties of the plasma-treated samples’ surfaces were evaluated by water contact angle goniometry (WCA), atomic force microscopy (AFM), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS). The best result concerning the water contact angle reduction was from 83° to 29.7° for the PMMA material. The ageing studies of the PMMA plasma-modified surface showed long term (100 h) improved wettability. As a result of plasma treating, changes in the samples surface roughness parameters were observed, however their dependence on the number of plasma scans is irregular. The ATR-FTIR spectra of the PMMA plasma-treated surfaces showed only slight changes in comparison with the spectra of an untreated sample. The more significant differences were demonstrated by XPS measurements indicating the surface chemical composition changes after plasma treatment and revealing the oxygen to carbon ratio increase from 0.1 to 0.4.

High Temperature Thermoelectric Device Concept Using Large Area PN Junctions

2014 ◽  
Vol 43 (6) ◽  
pp. 2376-2383 ◽  
Author(s):  
R. Chavez ◽  
S. Angst ◽  
J. Hall ◽  
J. Stoetzel ◽  
V. Kessler ◽  
...  
Keyword(s):  
High Temperature ◽  
Thermoelectric Device ◽  
Large Area ◽  
Pn Junctions

The small spacecraft with a magnetic sail on high-temperature superconductors

2021 ◽  
pp. 51-61
Author(s):  
Timur Sh. KOMBAEV ◽  
Mikhail K. ARTEMOV ◽  
Valentin K. SYSOEV ◽  
Dmitry S. DEZHIN
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
High Temperature ◽  
Shape Memory ◽  
New Technologies ◽  
High Temperature Superconductors ◽  
Solar Wind Plasma ◽  
Large Area ◽  
Small Spacecraft ◽  
Shape Memory Materials

It is proposed to develop a small spacecraft for an experiment using high-temperature superconductors (HTS) and shape memory materials. The purpose of the experiment is to test a technological capability of creating a strong magnetic field on the small spacecraft using HTS and shape memory materials for deployed large-area structures, and study the magnetic field interaction with the solar wind plasma and the resulting force impact on the small spacecraft. This article is of a polemical character and makes it possible to take a fresh look at the applicability of new technologies in space-system engineering. Key words: high-temperature superconductors, shape memory materials, solar wind, spacecraft.

Scaling Behavior of Superheater Tube Alloys in ASME High Temperature Steam Research Tests at 1100–1500 F

1962 ◽  
Vol 84 (3) ◽  
pp. 223-257 ◽  
Author(s):  
F. Eberle ◽  
C. H. Anderson
Keyword(s):  
High Temperature ◽  
Chemical Composition ◽  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Scaling Behavior ◽  
Effect Of Temperature ◽  
Relative Resistance ◽  
Superheater Tube ◽  
Shock Resistance ◽  
High Temperature Steam

The scales formed on seven ferritic and ten austenitic types of commercial tubing presently in use and of potential future use for superheater service were examined after 6, 12, and 18 months’ exposure to air and to flowing steam of 2000 psi at temperatures of 1100, 1200, 1350, and 1500 F. The effect of temperature and time of exposure on the adherence, thermal-shock resistance, thickness, structure, and chemical composition of the scales was investigated and the relative resistance to scaling of the various alloys evaluated.

The Formation of an Epitaxial-Graphene Cap Layer for Post-Implantation High Temperature Annealing of SiC and its In Situ Removal by Si-Vapor Etching

2011 ◽  
Vol 679-680 ◽  
pp. 777-780 ◽  
Author(s):  
Shoji Ushio ◽  
Ayumu Adachi ◽  
Kazuhiro Matsuda ◽  
Noboru Ohtani ◽  
Tadaaki Kaneko
Keyword(s):  
High Temperature ◽  
Graphene Layer ◽  
Treatment Method ◽  
Etch Depth ◽  
High Temperature Annealing ◽  
Large Area ◽  
Vapor Flux ◽  
Precise Control ◽  
Post Implantation

As a new graphene functionality applicable to post-implantation high temperature annealing of SiC, a method of in situ formation and removal of large area epitaxial few-layer graphene on 4H-SiC(0001) Si-face is proposed. It is demonstrated that the homogeneous graphene layer formed by Si sublimation can be preserved without the decomposition of the underlying SiC substrate even in the excess of 2000 oC in ultrahigh vacuum. It is due to the existence of the stable (6√3×6√3) buffer layer at the interface. To ensure this cap function, the homogeneity of the interface must be guaranteed. In order to do that, precise control of the initial SiC surface flatness is required. Si-vapor etching is a simple and versatile SiC surface pre/post- treatment method, where thermally decomposed SiC surface is compensated by a Si-vapor flux from Si solid source in the same semi-closed TaC container. While this Si-vapor etching allows precise control of SiC etch depth and surface step-terrace structures, it also provides a “decap” function to remove of the graphene layer. The surface properties after the each process were characterized by AFM and Raman spectroscopy.

scholarly journals Formation of Intermediate Phases and Supersaturated Solid Solution in Al-Cu System during Diffusion

2018 ◽  
Vol 383 ◽  
pp. 31-35 ◽  
Author(s):  
Alexey Rodin ◽  
Nataliya Goreslavets
Keyword(s):  
Phase Diagram ◽  
Solid Solution ◽  
High Temperature ◽  
Chemical Composition ◽  
Low Temperature ◽  
Supersaturated Solid Solution ◽  
Diffusion Processes ◽  
Equilibrium Phase ◽  
Equilibrium Phase Diagram ◽  
Intermediate Phases

The study of diffusion processes in the aluminum - copper system was carried out at the temperature 350 and 520 °C. Special attention was paid on the chemical composition of the system near Al/Cu interface. It was determined that the intermediate phases in the system, corresponding to the equilibrium phase diagram, were not formed at low temperature. At high temperature the intermediate phases forms starting with Cu - rich phases. In both cases supersaturated solid solution of copper in aluminum could be observed near the interface.

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