Study on the Compression-Resilience and Sealing Performance of New Metal-to-Metal Contact Gasket

The compression-resilience performance of new metal-to-metal contact (MMC) gasket at different temperatures was studied by compression-resilience test, and the influences on sealing performance of gasket caused by internal pressure of medium and assembly stress were studied by sealing test. Then the influences on performance of gasket caused by internal pressure of medium, bolt pretightening force, and temperature were studied through finite element method of ANSYS. According to the results of test and numerical analysis, conclusions are as follows: The new MMC gasket has good high-temperature stability from results of tests at different temperatures. When the MMC occurs between flange and gasket, the contact stress of new MMC gasket is about 50 MPa. When applying loads, the limiting ring of gasket is able to bear parts of bolt loads, and when reducing loads, its resilience can compensate loss of gasket stress. In this case, the stress on sealing surface of gasket remains stable so that the leakage rate can keep in a stable range. Because of its unique structure in design, the inner contact stress of new MMC gasket increases with the rise of internal pressure of medium so that in a certain range, the leakage rate changes gently, which shows that the gasket has a certain self-sealing ability. Besides, the new MMC gasket is able to adapt to high temperature and fluctuation of internal pressure of medium.

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Evaluation of High-Temperature Performance of Asphalt Mixtures Based on Climatic Conditions

Coatings ◽

10.3390/coatings10060535 ◽

2020 ◽

Vol 10 (6) ◽

pp. 535

Author(s):

Yan Mu ◽

Zhen Fu ◽

Jian Liu ◽

Chen Li ◽

Wenhao Dong ◽

...

Keyword(s):

High Temperature ◽

Dynamic Stability ◽

Asphalt Mixture ◽

Temperature Stability ◽

Climatic Conditions ◽

Asphalt Mixtures ◽

High Temperature Stability ◽

Long Duration ◽

Different Temperatures ◽

Modified Formula

The dynamic stability of a rutting test does not optimally reflect the high-temperature stability of asphalt mixtures. In this study, a rutting test was performed over a long duration (4 h) at different temperatures (40, 50, 60, 70 °C) for three asphalt mixtures, namely, matrix AC-16, SMA-16, and modified AC-16 asphalt mixtures. Subsequently, the temperature rutting rate was obtained after considering the annual temperature conditions of Guangdong and Beijing in China. Because the conditions of the rutting test were different from that of the actual pavement, the rut depth was calculated using a modified temperature rutting rate. This modification considered four factors: wheel trace distribution, temperature, pavement thickness, and loading rate. The calculation of the temperature rutting rate considered the climatic conditions and utilized the rutting deformation data from hour 1–4 of the rutting tests, during which the asphalt mixture was in a stable creep period. Thus, the high-temperature stability of the asphalt mixture was reflected more scientifically by the temperature rutting rate than the dynamic stability. The high-temperature rut-resistance of the asphalt mixture was found to improve significantly after the introduction of two additives (anti-rutting agent and lignin fiber). The modified formula for rut depth can realistically predict the annual rutting depth for three asphalt mixtures in a one-way driving pavement.

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High Temperature Stability of Oxygen Functionalized Epitaxial Graphene/Metal Contact Interfaces

Materials Science Forum ◽

10.4028/www.scientific.net/msf.740-742.145 ◽

2013 ◽

Vol 740-742 ◽

pp. 145-148

Author(s):

V. Karthik Nagareddy ◽

Sandra C. Hernández ◽

Virginia D. Wheeler ◽

Luke O. Nyakiti ◽

Rachael L. Myers-Ward ◽

...

Keyword(s):

Activation Energy ◽

High Temperature ◽

Contact Resistance ◽

Sheet Resistance ◽

Temperature Stability ◽

Epitaxial Graphene ◽

Metal Contact ◽

Electrical Characteristics ◽

Functionalized Graphene ◽

High Temperature Stability

The electrical characteristics of oxygen functionalized epitaxial graphene and Ti/Au metal contact interfaces were systematically investigated as a function of temperature. As the temperature was increased from 300 K to 673 K, the contact resistance and the sheet resistance decreased by 75% and 33%, respectively. The resistance of oxygen functionalized graphene vs temperature exhibited Arrhenius type behavior with activation energy of 38 meV. The results showed no hysteresis effects in resistance measurements over the temperatures studied here, suggesting the contact interfaces remain stable at high temperatures.

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High Temperature Stability of Fepure-Si3N4 in Reducing Atmosphere

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.952.11 ◽

2014 ◽

Vol 952 ◽

pp. 11-15

Author(s):

Bin Li ◽

Jun Hong Chen ◽

Jin Dong Su

Keyword(s):

High Temperature ◽

Silicon Nitride ◽

Temperature Stability ◽

High Temperature Stability ◽

Reducing Atmosphere ◽

Xrd Diffraction ◽

Calculation Results ◽

Different Temperatures ◽

The Stability ◽

Main Components

Iron and silicon nitride powders were mixed in a certain proportion and compacted, then Fepure-Si3N4 were prepared by heating the samples in reducing atmosphere at 1100°C, 1300°C and 1500 °C, respectively. The stability of Fepure-Si3N4 prepared at different temperatures was analyzed by XRD diffraction and theoretical thermodynamics calculation. Results show that the main components of Fepure-Si3N4 at high temperatures in reducing atmosphere are Si3N4 and Si2N2O; Iron exists in Fepure-Si3N4 at 1100°C, and iron had largely converted to Fe3Si phase at 1300°C and 1500°C, which is in accordance with the result of thermodynamic theoretical calculation.

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UNS N06455

Alloy Digest ◽

10.31399/asm.ad.ni0367 ◽

1989 ◽

Vol 38 (1) ◽

Keyword(s):

Corrosion Resistance ◽

High Temperature ◽

Stress Corrosion Cracking ◽

Temperature Stability ◽

Heat Treating ◽

High Ductility ◽

High Temperature Stability ◽

Nickel Chromium ◽

Long Time ◽

Resistance To Stress

Abstract UNS NO6455 is a nickel-chromium-molybdenum alloy with outstanding high-temperature stability as shown by high ductility and corrosion resistance even after long-time aging in the range 1200-1900 F. The alloy also has excellent resistance to stress-corrosion cracking and to oxidizing atmospheres up to 1900 F. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Ni-367. Producer or source: Nickel and nickel alloy producers.

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UNS R54620

Alloy Digest ◽

10.31399/asm.ad.ti0086 ◽

1987 ◽

Vol 36 (7) ◽

Keyword(s):

Titanium Alloy ◽

High Temperature ◽

Time Use ◽

Temperature Stability ◽

High Strength ◽

Heat Treating ◽

High Temperature Stability ◽

Beta Titanium Alloy ◽

Beta Titanium ◽

Long Time

Abstract UNS No. R54620 is an alpha-beta titanium alloy. It has an excellent combination of tensile strength, creep strength, toughness and high-temperature stability that makes it suitable for service to 1050 F. It is recommended for use where high strength is required. It has outstanding advantages for long-time use at temperatures to 800 F. This datasheet provides information on composition, physical properties, elasticity, tensile properties, and bend strength as well as creep. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Ti-86. Producer or source: Titanium alloy mills.

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