Modifications of thin coatings by heat treatment: Behavior of redeposited material on the first wall of fusion devices during plasma wall interaction

1986 ◽  
Vol 4 (6) ◽  
pp. 3050-3054
Author(s):  
J. Linke ◽  
H. Bolt ◽  
K. Koizlik ◽  
H. Nickel ◽  
E. Wallura ◽  
...  
Keyword(s):  
Heat Treatment ◽  
First Wall ◽  
Thin Coatings ◽  
Wall Interaction

Mechanical Properties of Pyrolytic "SiOCN" Thin Coatings

1993 ◽  
Vol 308 ◽  
Author(s):  
Sandrine Bec ◽  
André Tonck ◽  
Jean-Luc Loubet
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Ceramic Coatings ◽  
Optical Observation ◽  
Thin Coatings ◽  
Polymer Precursors ◽  
Polymeric State

ABSTRACTPyrolysis of polymer precursors (polysilazane) is a technologically and economically interesting way to produce thin ceramic coatings. However, many cracks appear and decohesion occurs during pyrolysis when the ceramic coatings (SiOCN) are thicker than 0.5 micrometers. In order to understand these cracking phenomena, the coatings are mechanically characterized by nanoindentation at different stages of the pyrolysis heat treatment.During pyrolysis, the cracking temperature is detected by in-situ optical observation. The thickness of the coatings varies during pyrolysis from 3 micrometers at the polymeric state to 1 micrometer at the ceramic state. The coatings' properties, hardness and Young's modulus are evaluated after heat treatment, taking into account the substrate's influence. A large variation of these properties occurs at the cracking temperature. Both the hardness and the Young's modulus are multiplied by a factor of 10. By analysing these results, we show that cracking is correlated with the evolution of the coatings' mechanical properties during the transformation.

scholarly journals Modelling of plasma-edge and plasma–wall interaction physics at JET with the metallic first-wall

2016 ◽  
Vol T167 ◽  
pp. 014078 ◽  
Author(s):  
S Wiesen ◽  
M Groth ◽  
S Brezinsek ◽  
M Wischmeier ◽  
Keyword(s):  
Plasma Edge ◽  
First Wall ◽  
Wall Interaction

Chapter 10: Plasma-Wall Interaction and First-Wall Materials in ASDEX Upgrade

2003 ◽  
Vol 44 (3) ◽  
pp. 692-707 ◽  
Author(s):  
Rudolf Neu ◽  
Arne Kallenbach ◽  
Karl Krieger ◽  
Volker Rohde ◽  
Joachim Roth
Keyword(s):  
First Wall ◽  
Wall Materials ◽  
Wall Interaction

scholarly journals Suppression of first-wall interaction in negative triangularity plasmas on TCV

2021 ◽  
Vol 61 (3) ◽  
pp. 034003
Author(s):  
W. Han ◽  
N. Offeddu ◽  
T. Golfinopoulos ◽  
C. Theiler ◽  
C.K. Tsui ◽  
...  
Keyword(s):  
First Wall ◽  
Wall Interaction

Review of Wall Conditioning and Wall Materials for Fusion Research Devices

MRS Bulletin ◽  
1990 ◽  
Vol 15 (7) ◽  
pp. 42-46 ◽  
Author(s):  
Robert A. Langley
Keyword(s):  
Chemical Interaction ◽  
Wall Material ◽  
First Wall ◽  
Fusion Plasma ◽  
Fusion Research ◽  
Wall Materials ◽  
Radiative Losses ◽  
Wall Interaction ◽  
Hydrogenic Ions ◽  
Plasma Impurities

Wall materials for fusion research must meet stringent requirements. The purity of a fusion plasma is critical to obtaining meaningful results during fusion plasma experiments. The concentration of impurity ions in the plasma must be kept low because impurities result in radiative losses that at best decrease the efficiency of the plasma “burn” and at worst prevent ignition completely. Radiative losses scale with the effective charge, Z, of the plasma. Radiative losses due to bremsstrahlung are proportional to Z2; those due to recombination are proportional to Z4. Figure 1 shows the impurity concentration above which ignition cannot be achieved as a function of impurity atomic number for an experimental power reactor. The advantage of using a low-Z material as the first wall of a fusion machine (i.e., as the plasma-facing material) is evident.The major plasma impurities observed in most experiments are oxygen, carbon, and first-wall material. These impurities are introduced into the plasma by many mechanisms, including outgassing, desorption, chemical interaction, sputtering, and evaporation. Chemical and physical interactions between the first wall and the energetic hydrogenic ions produced in the plasma are important factors in impurity production. (Here “hydrogen” refers to hydrogen and its isotopes, deuterium and tritium.)The energy contained in the plasma can be quite large (many megajoules) and can interact with the first wall on a short rime-scale (e.g., a millisecond). It is possible that no material will prove suitable for all operational scenarios. Therefore, the burden of reducing the plasma/first-wall interaction to an acceptable level rests on both plasma and materials scientists.

scholarly journals Plasma–wall interaction in laser inertial fusion reactors: novel proposals for radiation tests of first wall materials

2012 ◽  
Vol 54 (12) ◽  
pp. 124051 ◽  
Author(s):  
J Alvarez Ruiz ◽  
A Rivera ◽  
K Mima ◽  
D Garoz ◽  
R Gonzalez-Arrabal ◽  
...  
Keyword(s):  
Inertial Fusion ◽  
Fusion Reactors ◽  
First Wall ◽  
Wall Materials ◽  
Wall Interaction

The Precipitation of Si in AlCuSi Thin Films

1973 ◽  
Vol 31 ◽  
pp. 34-35 ◽  
Author(s):  
R. M. Anderson
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Heat Treatment ◽  
Solid Solution ◽  
Integrated Circuit ◽  
Copper Film ◽  
Solution Concentration ◽  
X Ray ◽  
Silicon Thin Films ◽  
Before And After

Aluminum-copper-silicon thin films have been considered as an interconnection metallurgy for integrated circuit applications. Various schemes have been proposed to incorporate small percent-ages of silicon into films that typically contain two to five percent copper. We undertook a study of the total effect of silicon on the aluminum copper film as revealed by transmission electron microscopy, scanning electron microscopy, x-ray diffraction and ion microprobe techniques as a function of the various deposition methods.X-ray investigations noted a change in solid solution concentration as a function of Si content before and after heat-treatment. The amount of solid solution in the Al increased with heat-treatment for films with ≥2% silicon and decreased for films <2% silicon.

The influence of heat treatment on the fiber/matrix interface in a SiC-reinforced glassceramic

1988 ◽  
Vol 46 ◽  
pp. 742-743
Author(s):  
E. Bischoff ◽  
O. Sbaizero
Keyword(s):  
Heat Treatment ◽  
Aluminum Silicate ◽  
Lithium Aluminum ◽  
Interfacial Region ◽  
Specimen Preparation ◽  
Crack Wake ◽  
Pull Out ◽  
Annealed Material ◽  
Ultrasonic Drilling ◽  
Fiber Matrix Interface

Fiber or whisker reinforced ceramics show improved toughness and strength. Bridging by intact fibers in the crack wake and fiber pull-out after failure contribute to the additional toughness. These processes are strongly influenced by the sliding and debonding resistance of the interfacial region. The present study examines the interface in a laminated 0/90 composite consisting of SiC (Nicalon) fibers in a lithium-aluminum-silicate (LAS) glass-ceramic matrix. The material shows systematic changes in sliding resistance upon heat treatment.As-processed samples were annealed in air at 800 °C for 2, 4, 8, 16 and 100 h, and for comparison, in helium at 800 °C for 4 h. TEM specimen preparation of as processed and annealed material was performed with special care by cutting along directions having the fibers normal and parallel to the section plane, ultrasonic drilling, dimpling to 100 pm and final ionthinning. The specimen were lightly coated with Carbon and examined in an analytical TEM operated at 200 kV.

Strain-induced martensite effects on transgranular carbide precipitation in type 304 stainless steels

1991 ◽  
Vol 49 ◽  
pp. 604-605
Author(s):  
A.H. Advani ◽  
L.E. Murr ◽  
D. Matlock
Keyword(s):  
Heat Treatment ◽  
Grain Boundary ◽  
Stress Corrosion Cracking ◽  
Stainless Steels ◽  
Deformation Twin ◽  
Austenitic Stainless Steels ◽  
Carbide Precipitation ◽  
Strain Induced Martensite ◽  
Type 304

Thermomechanically induced strain is a key variable producing accelerated carbide precipitation, sensitization and stress corrosion cracking in austenitic stainless steels (SS). Recent work has indicated that higher levels of strain (above 20%) also produce transgranular (TG) carbide precipitation and corrosion simultaneous with the grain boundary phenomenon in 316 SS. Transgranular precipitates were noted to form primarily on deformation twin-fault planes and their intersections in 316 SS.Briant has indicated that TG precipitation in 316 SS is significantly different from 304 SS due to the formation of strain-induced martensite on 304 SS, though an understanding of the role of martensite on the process has not been developed. This study is concerned with evaluating the effects of strain and strain-induced martensite on TG carbide precipitation in 304 SS. The study was performed on samples of a 0.051%C-304 SS deformed to 33% followed by heat treatment at 670°C for 1 h.

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