High Temperature Oxidation and Corrosion of Silicon-Based Nonoxide Ceramics

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]

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Stability of Nanometer-Thick Layers in Hard Coatings

MRS Bulletin ◽

10.1557/mrs2003.57 ◽

2003 ◽

Vol 28 (3) ◽

pp. 169-172 ◽

Cited By ~ 65

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.

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REFRACTALOY 70

Alloy Digest ◽

10.31399/asm.ad.co0002 ◽

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.

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TIMETAL 6-2-4-2

Alloy Digest ◽

10.31399/asm.ad.ti0140 ◽

2007 ◽

Vol 56 (6) ◽

Keyword(s):

Tensile Strength ◽

High Temperature ◽

Physical Properties ◽

Tensile Properties ◽

Creep Strength ◽

Temperature Stability ◽

Heat Treating ◽

High Temperature Stability ◽

Temperature Performance

Abstract Timetal 6-2-4-2 has a combination of tensile strength, creep strength, toughness, and high-temperature stability for long-term application at temperatures up to 538 deg C (1000 deg F). This datasheet provides information on composition, physical properties, microstructure, elasticity, and tensile properties as well as creep. It also includes information on high temperature performance as well as forming, heat treating, and joining. Filing Code: TI-140. Producer or source: Timet.

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High temperature Au-based solder reliability in electronic packages for harsh environments

International Symposium on Microelectronics ◽

10.4071/isom-2011-tp6-paper6 ◽

2011 ◽

Vol 2011 (1) ◽

pp. 000438-000445

Author(s):

M.F. Sousa ◽

S. Riches ◽

C. Johnston ◽

P.S. Grant

Keyword(s):

High Temperature ◽

Thermal Cycling ◽

Thermal Shock ◽

Microstructural Analysis ◽

Temperature Stability ◽

Acoustic Microscopy ◽

Harsh Environments ◽

Electronic Packages ◽

High Temperature Stability ◽

Die Attach

The operation of electronic packages in high temperature environments is a significant challenge for the microelectronics industry, and poses a challenge to the traditional temperature limit of 125°C for high electronic systems, such as those used in down-hole, well-logging and aero-engine applications. The present work aims to develop understanding of how and why attach materials for Si dies degrade/fail under harsh environments by investigating high temperature Au based solders. Au-2wt%Si eutectic melts at < 400°C and offers high temperature stability but high temperature processing and complex manufacturing steps are the major drawbacks. Changes in the die attach material were investigated by isothermal ageing at 350°C, thermal shock and thermal cycling treatments. Die attach reliability investigated by thermal shock and thermal cycling showed that the bonded area degraded. Nevertheless, most of the samples tested had high bonded area ranging from 92.5 to 97.5%. The failure behaviour of the die attach materials included cracking of die and/or attach material, delamination and voiding. Scanning acoustic microscopy images provided a rapid assessment of delamination and other defects and their location within the package. Microstructural analysis and die shear testing were also carried out, along with the high temperature endurance of a SOI test chip for signal conditioning and processing applications at 250°C. All functions evaluated have shown stable performance at 250°C for up to 9000 hours.

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

Alloy Digest ◽

10.31399/asm.ad.ti0185 ◽

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.

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An Experimental Study on Properties of Pre-Coated Aggregates Grouting Asphalt Concrete for Bridge Deck Pavement

Materials ◽

10.3390/ma14185323 ◽

2021 ◽

Vol 14 (18) ◽

pp. 5323

Author(s):

Zhicheng Xiao ◽

Wenke Huang ◽

Kuanghuai Wu ◽

Guihai Nie ◽

Hafiz Muhammad Zahid Hassan ◽

...

Keyword(s):

High Temperature ◽

Asphalt Concrete ◽

Bridge Deck ◽

Asphalt Binder ◽

Microstructural Analysis ◽

Temperature Stability ◽

Fatigue Performance ◽

High Temperature Stability ◽

Pavement Materials ◽

Bridge Deck Pavement

Epoxy asphalt concrete, mortar asphalt concrete and Gussasphalt concrete are commonly used types of deck pavement materials in bridge deck pavement engineering. However, achieving the high-temperature stability and anti-fatigue performance of the deck pavement materials is still challenging. In order to reduce the rutting and cracking risks of the asphalt mixture, this paper proposed pre-coated aggregates grouting asphalt concrete (PGAC) for bridge deck pavement. Laboratory tests were conducted to determine the optimum grouting materials and to evaluate the mechanical performances of the PGAC material. Test results showed that the mechanical properties for PGAC with grouting material of high-viscosity-modified asphalt binder blending with mineral filler were superior to that of GMA-10 used for the Hong Kong-Zhuhai-Macau Bridge deck pavement. Microstructural analysis showed that the PGAC had a more stable skeleton structure compared to other typical aggregate mixtures. This study highlights the performances of the proposed PGAC and sheds light on the deck pavement material improvement of both high-temperature stability and anti-fatigue performance that could be achieved.

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