Stability of Nanometer-Thick Layers in Hard Coatings

MRS Bulletin ◽  
2003 ◽  
Vol 28 (3) ◽  
pp. 169-172 ◽  
Author(s):  
Scott A. Barnett ◽  
Anita Madan ◽  
Ilwon Kim ◽  
Keith Martin
Keyword(s):  
High Temperature ◽  
Elevated Temperatures ◽  
Temperature Stability ◽  
Hexagonal Wurtzite Structure ◽  
Thin Layers ◽  
Hard Coatings ◽  
High Temperature Stability ◽  
The Stability ◽  
Hardness Values ◽  
Thick Layers

AbstractThis article reviews two topics related to the stability of hard coatings composed of nanometer-thick layers: epitaxial stabilization and high-temperature stability. Early work on nanolayered hard coatings demonstrated large hardness increases as compared with monolithic coatings, but it was subsequently found that the layers interdiffused at elevated temperatures. More recently, it has been shown that nanolayers exhibit good stability at elevated temperatures if the layer materials are thermodynamically stable with respect to each other and are able to form low-energy coherent interfaces. This article discusses metal/nitride, nitride/nitride, and nitride/boride nanolayers that exhibit good high-temperature stability and hardness values that are maintained (or even increase) after high-temperature annealing. Epitaxial stabilization of nonequilibrium structuresin thin layers is a well-known phenomenon that has been applied to hard nitride materials. In particular, AlN, which crystallizes in the hexagonal wurtzite structure in bulk form, was stabilized in the rock-salt cubic structure in nitride/nitride nanolayers (e.g., AlN/TiN). These results and the current understanding of epitaxial stabilization in hard nanolayers are discussed.

Experimental Study of Typical Graded Asphalt Mixture about Dynamic Stability at High Temperature

2016 ◽  
Vol 858 ◽  
pp. 300-304
Author(s):  
Zhen Fu Chen ◽  
Dan Wu ◽  
Qiu Wang Tao ◽  
Yuan Chu Gan
Keyword(s):  
Experimental Data ◽  
Experimental Study ◽  
High Temperature ◽  
Asphalt Mixture ◽  
Temperature Stability ◽  
Specimen Thickness ◽  
High Temperature Stability ◽  
Change Trend ◽  
Comparison And Analysis ◽  
The Stability

The high temperature stability of AC-16, AC-13, AC-20 under specimen thickness of 5cm and 6cm is studied through indoor asphalt mixture high rutting test, Through comparison and analysis about experimental data, it is found that the stability of AC-16, AC-13, AC-20 asphalt mixture at high- temperature decreases in turn. It is shown that thickness changes did not affect the change trend of the high temperature stability under gradation change, and the stability of AC-16 at high-temperature is the best, the AC-13 is second and the AC-20 is less.

Highly Stable Ir-Ta-O Electrode for Ferroelectric Material Deposition

2000 ◽  
Vol 655 ◽  
Author(s):  
Fengyan Zhang ◽  
Sheng Teng Hsu ◽  
Jer-shen Maa ◽  
Yoshi Ono ◽  
Ying Hong ◽  
...  
Keyword(s):  
High Temperature ◽  
Bottom Electrode ◽  
Temperature Stability ◽  
Gate Oxide ◽  
Ferroelectric Material ◽  
High Temperature Stability ◽  
Material Deposition ◽  
Long Time ◽  
The Stability ◽  
Thin Gate Oxide

AbstractIr-Ta-O composite bottom electrode has extraordinary high temperature stability. It can maintain good conductivity and integrity even after 5min annealing at 1000 °C in oxygen ambient. The thermal stability of Ir-Ta-O on different substrates has been studied. It shows that Ir-Ta-O is also very stable on Si and SiO2 substrates. No hillock formation and peelings of the bottom electrode were observed after high temperature and long time annealing in O2 ambient. SEM, TEM, XRD, and AES have been used to characterize the Ir-Ta-O film and the interfaces between Ir-Ta-O bottom electrode and Si or SiO2 substrate. The composition and conductivity changes of the electrode during oxygen ambient annealing and the interdiffusion issue will be discussed. Furthermore, Ir-Ta-O/SiO2/Si capacitor with 30Å gate oxide was fabricated and the C-V and I-V characteristics were measured to confirm the stability of Ir-Ta-O on thin gate oxide.

High Temperature Oxidation and Corrosion of Silicon-Based Non-Oxide Ceramics

1999 ◽  
Vol 122 (1) ◽  
pp. 13-18 ◽  
Author(s):  
H. Klemm ◽  
M. Herrmann ◽  
C. Schubert
Keyword(s):  
High Temperature ◽  
Elevated Temperatures ◽  
Microstructural Analysis ◽  
Temperature Stability ◽  
Ambient Air ◽  
High Temperature Stability ◽  
Temperature Oxidation ◽  
Sic Ceramics ◽  
Silicon Based

The present study is focussed on the oxidation behavior of nonoxide silicon-based ceramics. Various Si3N4 and SiC ceramics were examined after long term oxidation tests (up to 5000 h) at 1500°C in ambient air. The damage mechanisms were discussed on the basis of a comprehensive chemical and microstructural analysis of the materials after the oxidation tests. The diffusion of oxygen into the material and its further reaction in the bulk of the material were found to be the most critical factors during long term oxidation treatment at elevated temperatures. However, the resulting damage in the microstructure of the materials can be significantly reduced by purposeful microstructural engineering. Using Si3N4/SiC and Si3N4/MoSi2 composite materials provides the possibility to improve the high temperature stability. [S0742-4795(00)00301-X]

REFRACTALOY 70

Alloy Digest ◽  
1961 ◽  
Vol 10 (8) ◽  
Keyword(s):  
High Temperature ◽  
Elevated Temperatures ◽  
Temperature Stability ◽  
Heat Treating ◽  
High Temperature Stability ◽  
Nickel Chromium ◽  
Temperature Performance ◽  
Westinghouse Electric Corporation ◽  
Oxidation Resistant ◽  
Westinghouse Electric

Abstract REFRACTALOY 70 is a super heat and oxidation resistant alloy containing high percentages of nickel, chromium, cobalt and molybdenum. It has an exceedingly low creep rate at elevated temperatures and shows marked high temperature stability. This datasheet provides information on composition, physical properties, hardness, and tensile properties as well as creep. It also includes information on high temperature performance as well as forming, heat treating, machining, and joining. Filing Code: Co-2. Producer or source: Westinghouse Electric Corporation. Originally published July 1953, revised August 1961.

SMITHS Ti-6Al-2Sn-4Zr-2Mo-Si

Alloy Digest ◽  
2021 ◽  
Vol 70 (12) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Titanium Alloy ◽  
High Temperature ◽  
Creep Resistance ◽  
Elevated Temperatures ◽  
Temperature Stability ◽  
High Strength ◽  
Heat Treating ◽  
High Temperature Stability ◽  
Alpha Titanium

Abstract Smiths Ti-6Al-2Sn-4Zr-2Mo-Si is a near-alpha titanium alloy that was developed for use at elevated temperatures. It exhibits high strength and toughness, excellent creep resistance, and high temperature stability at temperatures up 550 °C (1020 °F). This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as casting, heat treating, and joining. Filing Code: Ti-185. Producer or source: Smiths Metal Centres Limited.

Thermal Stability of Nanoscale Multilayered ZrAlN/ZrB2 Coatings

2005 ◽  
Vol 107 ◽  
pp. 137-140 ◽  
Author(s):  
D.J. Li ◽  
J.J. Zhang ◽  
Ming Xia Wang
Keyword(s):  
Thermal Stability ◽  
High Temperature ◽  
Partial Pressure ◽  
Layer Structure ◽  
Temperature Stability ◽  
Substrate Bias ◽  
High Temperature Stability ◽  
Dc Magnetron Sputtering ◽  
Hardness Values ◽  
Thermal Stability Of

Multilayered ZrAlN/ZrB2 coatings were synthesized using a multi-cathode dc magnetron sputtering technique. Effects of substrate bias and N2 gas partial pressure on structural, mechanical properties, as well as thermal stability were investigated. Low bias was beneficial to synthesis of nanolayers with weak internal stress. The nanolayers deposited at lower N2 partial pressure and substrate bias exhibited good high-temperature stability in the crystalline and layer structure, and hardness values were increased significantly after high-temperature annealing.

Evaluation and Application of Hard Coatings for Steam Turbine

2017 ◽  
Author(s):  
Liang Yan ◽  
Yujiro Nakatani ◽  
Masayuki Yamada ◽  
Toru Abe ◽  
Koichi Kitaguchi ◽  
...  
Keyword(s):  
High Temperature ◽  
Steam Turbine ◽  
Power Plants ◽  
Turbine Blades ◽  
Temperature Stability ◽  
Hard Coatings ◽  
High Temperature Stability ◽  
Creep Tests ◽  
Tialn Coating ◽  
Steam Turbine Blades

In order to improve solid particle erosion (SPE) resistance for steam turbine blades and nozzles, in corporation with Kobe Steel, Ltd., evaluation of hard coatings of TiN and TiAlN deposited by the Arc Ion Plating (AIP®) process was performed to verify applicability to an actual steam turbine. The results of high-temperature steam oxidation tests and room-temperature sand erosion tests showed that the TiAlN coating had high-temperature stability superior to that of the TiN coating, and erosion resistance far superior to that in the case of the conventional CrC thermal spray coating and boronizing treatment. High-temperature fatigue and creep tests showed that the characteristic strength of the blade material with the TiAlN coating was equal or superior to that of the base blade material. On the basis of the results of comprehensive evaluation, it was confirmed that the TiAlN hard coating has excellent applicability to an actual steam turbine and it was successfully applied to steam turbine blades of power plants in Japan.

The High Temperature Stability and Relaxation of UHV/CVD SiGe Thin Films

1992 ◽  
Vol 280 ◽  
Author(s):  
S. R. Stiffler ◽  
C. L. Stanis ◽  
M. S. Goorsky ◽  
K. K. Chan
Keyword(s):  
Thin Films ◽  
High Temperature ◽  
Misfit Dislocation ◽  
Stability Criterion ◽  
Temperature Stability ◽  
Dislocation Nucleation ◽  
Misfit Dislocations ◽  
High Temperature Stability ◽  
Nucleation Barrier ◽  
The Stability

ABSTRACT:: High temperature (950°C) annealing is used to stimulate relaxation in UHV/CVD SiGe thin films. It is found that the films are stable to thicknesses which exceed the stability criterion of Matthews and Blakeslee [1] by a small amount. In unstable films, the misfit dislocation density increases with annealing time, reaching a maximum value. For films which exceed the empirical stability criterion by a relatively small amount, the misfit dislocations relax the film to a strain given by the film thickness and the empirical stability criterion. However, large remnant strains are observed when the relaxation process introduces relatively high dislocation densities (≳5 misfits/micron). Associated with large remnant strains are a marked propensity for dislocation banding and looping deep into the substrate with extended annealing. These results are discussed with respect to the magnitude of the misfit dislocation nucleation barrier and the energy associated with interactions among misfit dislocations.

Research of Asphalt Mixtures High Temperature Stability

2013 ◽  
Vol 405-408 ◽  
pp. 1871-1874
Author(s):  
Gen Chuan Luo
Keyword(s):  
High Temperature ◽  
Asphalt Pavement ◽  
Asphalt Mixture ◽  
Influence Factors ◽  
Temperature Stability ◽  
Asphalt Mixtures ◽  
High Temperature Stability ◽  
Air Voids ◽  
Asphalt Content ◽  
The Stability

Rutting is one of the most hazardous damage form of asphalt pavement.But,owing to itself inherent in the viscoelastic characteristics of asphalt mixture,the diversity of factors influencing the high temperature of asphalt pavement anti-rutting performance and the complexity of rut formation,this three reasons make ruts become a worldwide problem.Starting from the mixture.This article analyzed the influence factors of the rutting resistance of asphalt mixture at high temperature.For asphalt mixture, through the experimental data, the research status at home and abroad, from the type of asphalt, asphalt content, grading of aggregates and air voids four aspects analysis and study the influence factors of the stability of asphalt mixture at high temperature.

High Temperature Stability of Oxycarbide Glasses

1992 ◽  
Vol 271 ◽  
Author(s):  
Hanxi Zhang ◽  
Carlo G. Pantano
Keyword(s):  
High Temperature ◽  
Hydrogen Concentration ◽  
Network Structure ◽  
Sol Gel ◽  
Temperature Stability ◽  
Silicon Oxycarbide ◽  
High Temperature Stability ◽  
Sol Gel Process ◽  
Silicon Oxycarbide Glasses ◽  
The Stability

ABSTRACTThe stability of silicon oxycarbide glasses has been studied at temperatures up to 1500°C. The silicon oxycarbide glasses were synthesized using a sol/gel process. The pyrolysis treatment in argon influenced the structure and composition of the synthesized glasses, and in turn, their high temperature stability in oxidizing atmosphere. The oxycarbide glasses pyrolyzed at > 1000°C had lower hydrogen concentration and a more polymerized network structure, and thereby were more resistant to oxidation and crystallization at higher temperatures.

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