Design and engineering of carbon brakes

1980 ◽  
Vol 294 (1411) ◽  
pp. 583-590 ◽  
Keyword(s):  
Vapour Deposition ◽  
Chemical Vapour ◽  
Carbon Composite ◽  
Major Constituent ◽  
Control Practice ◽  
Weight Saving ◽  
Property Evaluation ◽  
Design And Manufacturing ◽  
Successful Design ◽  
Steel Design

The need for weight saving on Concorde stimulated the development of lightweight aircraft brakes. Carbon has long been recognized as a major constituent of brake friction materials and a carbon carbon composite has been engineered to provide adequate structural, thermal and friction characteristics for these disks. The use of carbon brake disks offered a 60 % weight saving compared with steel. Design of the composite is particular to the application. Orientation of the fibres on account of stress and heat flow requirements is vital to the achievement of a successful design. The material is considerably anisotropic and represents a compromise between strength and thermal properties, and manufacturing costs. Dunlop selected the chemical vapour deposition of carbon into a carbon fibre lay-up as the method of manufacture of the composite for Concorde brakes. The introduction of an incompletely developed process and a new composite brought novel problems to both design and manufacturing staff. Material property evaluation and extensive quality control practice played a major role.

Ultrananocrystalline Diamond / Amorphous Carbon Composite Films – Deposition, Characterization and Applications

2010 ◽  
Vol 159 ◽  
pp. 49-55
Author(s):  
Cyril Popov ◽  
Wilhelm Kulisch ◽  
Christo Petkov ◽  
Johann Peter Reithmaier
Keyword(s):  
Amorphous Carbon ◽  
Vapour Deposition ◽  
Microwave Plasma ◽  
Composite Films ◽  
Chemical Vapour ◽  
Polycrystalline Diamond ◽  
Carbon Composite ◽  
Bonding Structure ◽  
Ultrananocrystalline Diamond ◽  
Plasma Chemical Vapour Deposition

UNCD/a-C composite films have been deposited by microwave plasma chemical vapour deposition from methane/nitrogen mixtures with 17% CH4 in the temperature range 500-770°C on various substrates such as monocrystalline silicon wafers, polycrystalline diamond, c-BN, TiN, GaAs, and other materials of technological interest. The resulting films have been thoroughly characterized with respect to their morphology, crystallinity, composition, and bonding structure. It was found that they are composed of diamond nanocrystallites (3-5 nm in diameter) surrounded by 1-1.5 nm amorphous carbon grain boundary material; the ratio of the volume fractions of crystalline and amorphous phase is close to unity. The investigations of the application-relevant properties of the UNCD/a-C films revealed that they are attractive for a number of mechanical, tribological, structural, and biomedical applications.

Electron microscope characterization of MOCVD-grown gap layers on Si

1986 ◽  
Vol 44 ◽  
pp. 724-725
Author(s):  
K.M. Jones ◽  
M.M. Al-Jassim ◽  
J.M. Olson
Keyword(s):  
Atmospheric Pressure ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Organic Chemical ◽  
Lattice Match ◽  
Si Substrates ◽  
Metal Organic ◽  
Good Lattice ◽  
Antiphase Domains

The epitaxial growth of III-V semiconductors on Si for integrated optoelectronic applications is currently of great interest. GaP, with a lattice constant close to that of Si, is an attractive buffer between Si and, for example, GaAsP. In spite of the good lattice match, the growth of device quality GaP on Si is not without difficulty. The formation of antiphase domains, the difficulty in cleaning the Si substrates prior to growth, and the poor layer morphology are some of the problems encountered. In this work, the structural perfection of GaP layers was investigated as a function of several process variables including growth rate and temperature, and Si substrate orientation. The GaP layers were grown in an atmospheric pressure metal organic chemical vapour deposition (MOCVD) system using trimethylgallium and phosphine in H2. The Si substrates orientations used were (100), 2° off (100) towards (110), (111) and (211).

Low-pressure chemical vapour deposition of mullite coatings in a cold-wall reactor

1999 ◽  
Vol 09 (PR8) ◽  
pp. Pr8-395-Pr8-402 ◽  
Author(s):  
B. Armas ◽  
M. de Icaza Herrera ◽  
C. Combescure ◽  
F. Sibieude ◽  
D. Thenegal
Keyword(s):  
Chemical Vapour Deposition ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Low Pressure ◽  
Cold Wall ◽  
Pressure Chemical ◽  
Mullite Coatings

Thermodynamical and experimental conditions of hafnium carbide chemical vapour deposition

1999 ◽  
Vol 09 (PR8) ◽  
pp. Pr8-373-Pr8-380 ◽  
Author(s):  
P. Sourdiaucourt ◽  
A. Derré ◽  
P. Delhaès ◽  
P. David
Keyword(s):  
Chemical Vapour Deposition ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Hafnium Carbide ◽  
Experimental Conditions

Reduction of carbon impurities in aluminium nitride from time-resolved chemical vapour deposition using trimethylaluminum

2020 ◽  
Author(s):  
Polla Rouf ◽  
Pitsiri Sukkaew ◽  
Lars Ojamäe ◽  
Henrik Pedersen
Keyword(s):  
Chemical Vapour Deposition ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Aluminium Nitride ◽  
Methyl Groups ◽  
Time Resolved ◽  
Thermally Induced ◽  
Light Emitting ◽  
Carbon Impurities ◽  
Wide Range

<p>Aluminium nitride (AlN) is a semiconductor with a wide range of applications from light emitting diodes to high frequency transistors. Electronic grade AlN is routinely deposited at 1000 °C by chemical vapour deposition (CVD) using trimethylaluminium (TMA) and NH<sub>3</sub> while low temperature CVD routes to high quality AlN are scarce and suffer from high levels of carbon impurities in the film. We report on an ALD-like CVD approach with time-resolved precursor supply where thermally induced desorption of methyl groups from the AlN surface is enhanced by the addition of an extra pulse, H<sub>2</sub>, N<sub>2</sub> or Ar between the TMA and NH<sub>3</sub> pulses. The enhanced desorption allowed deposition of AlN films with carbon content of 1 at. % at 480 °C. Kinetic- and quantum chemical modelling suggest that the extra pulse between TMA and NH<sub>3</sub> prevents re-adsorption of desorbing methyl groups terminating the AlN surface after the TMA pulse. </p>

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