Cornell University

Jupiter Technologies, Inc.

Rishi Raj

Prakash Chandra Panda

Edgar R Seydel

Francis C Moon

Albert J Sievers

Sunggi Baik

Tae Won Noh

Stephen L Sass

Vera A Versteeg

C Thomas Avedisian

Fuh-Sheng Shieu

Sujata Jagota

Liang Yue

A liquid delivery system for a chemical vapor deposition apparatus, and a method of using the same employs one or more ultrasonic atomizing nozzles to inject one or more liquid precursor solutions directly into a CVD reactor chamber. The liquid delivery system can be operated either in a continuous mode or in a pulsed mode. In the pulsed mode, measured pulses of the liquid precursor solution are injected by the one or more ultrasonic atomizing nozzles so that control of film deposition rates as fine as monolayers per pulse can be obtained. Use of the ultrasonic nozzles insures that the liquid will be vaporized in the reactor chamber so that uniform deposition of films on one or more substrates in the reactor chamber is achieved.

Method and apparatus for CVD using liquid delivery system with an

Novel diamond thin films deposited on a metal or ceramic composite comprising a matrix having dispersed therein finely divided diamond or diamond-like particles are useful in improving the erosion resistance of materials used for long wave infrared transmitting applications such as domes and infrared windows.

Diamond and diamond-like films and coatings prepared by deposition on

New composites useful for infrared transmitting applications comprise a dispersion of small particles of diamonds in a matrix having infrared transmission properties (from about 1 to at least 10 .mu.m wavelength) and refractive index substantially similar to that of diamond. The composites exhibit mechanical toughness and durability 2-4 times that of the similarly treated matrix alone without adverse effect on optical properties.

Infra red diamond composites

A continuous thin film metal coated ceramic substrate is provided by employing intimate mixtures of transition element metal and element different from the transition element metal which is from the same group of the Periodic Table as the metallic or semimetallic atom of the ceramic of the substrate.

Non-beading, thin-film, metal-coated ceramic substrate

Shrinkage is substantially reduced or eliminated in the x-y plane during co-firing interposing predominantly ceramic layer between predominantly glass layers in the green multilayer assembly. The ceramic is preferably aluminum nitride.

Co-fired multilayer ceramic tapes that exhibit constrained sintering

Metal-ceramic interfaces of enhanced strength are produced by positioning bodies of ceramic oxides and transition element metals or alloys containing such in abutting relationship, and heating in air at a temperature ranging from 500.degree. C. to just below the melting point of the metal of the metal body to join said bodies and then subsequently heat treating said joined bodies in a reducing atmosphere at a temperature in the range of 300.degree. C. to 1200.degree. C. to form intermetallic compound layer at the interface.

Enhancing bonding at metal-ceramic interfaces

A non-contacting superconducting rotating assembly is described which includes a floating, unsupported and stable rotor. The assembly includes first and second bearings comprised of a material which exhibits Type II superconducting properties. The rotor includes a magnetic pole at each of its extremities, each pole resting in a bearing. The polar axis of each pole is colinear with the rotating axis of the rotor. A temperature bath is provided for maintaining the bearings at or below their critical superconducting temperature and a motive mechanism provides for rotation of the rotor. Each magnet pole is thereby levitated and adapted to rotate in a stable, non contacting position by the field and pinning effects generated by the associated bearing.

Superconducting rotating assembly

A non-contacting superconducting rotating assembly is described which includes a floating, unsupported and stable rotor. The assembly includes first and second bearings comprised of a material which exhibits Type II superconducting properties. The rotor includes a magnetic pole at each of its extremities, each pole resting in a bearing. The polar axis of each pole is colinear with the rotating axis of the rotor. A temperature bath is provided for maintaining the bearings at or below their critical superconducting temperature and a motive mechanism provides for rotation of the rotor. Each magnet pole is thereby levitated and adapted to rotate in a stable, non-contacting position by the field and pinning effects generated by the associated bearing.

A novel ceramic-ceramic composite of a uniform dispersion of silicon carbide fibers in a matrix of MgO.multidot.nAl.sub.2 O.sub.3 wherein n ranges from about 1 to about 4.5, said composite comprising by volume from 1 to 50% silicon carbide fibers and from 99 to 50% MgO.multidot.nAl.sub.2 O.sub.3. The composite is readily fabricated by forming a powder comprising a uniform dispersion of silicon carbide fibers in poorly crystalline phase comprising MgO and Al.sub.2 O.sub.3 in a mole ratio of n and either (a) hot pressing or preferably (b) cold pressing to form a preform and then forging utilizing a temperature in the range of 1100.degree. C. to 1900.degree. C. and a strain rate ranging from about 10.sup.-5 seconds .sup.-1 to about 1 seconds .sup.-1 so that surfaces cracks do not appear to obtain a shear deformation greater than 30%.

Composites comprising silicon carbide fibers dispersed in

The invention relates to producing relatively flaw free zirconia ceramic shapes requiring little or no matching by superplastic forging of a fully sintered or partially sintered preform. The preform is prepared by providing a starting powder comprising by weight from about 70% to about 100% zirconia and from about 0 to about 30% of stabilizing additives, e.g. commerically available TZ-3Y powder, cold pressing to obtain a preform of green density ranging from about 30% of theoretical density to about 75% of theoretical density and partially or fully sintering at atmospheric pressure, e.g. in argon or air at a temperature ranging from about 900.degree. C. to about 1900.degree. C. The superplastic forging is carried out by isothermally pressing the partially or fully sintered preform into substantially final shape utilizing a temperature and strain rate such that surface cracks do not occur, e.g. utilizing a temperature of 1310.degree. C., a substantially constant displacement rate based on an initial strain rate of 7.times.10.sup.-3 seconds .sup.-1 and open die or closed die processing in a graphite or metal die.

Superplastic forging of zirconia ceramics

Alpha-alumina whiskers are produced by forming a film of boehmite gel seeded with alpha-alumina seed material, preferably sapphire, and heating at 900.degree. C. to 1200.degree. C. for 5 minutes to 2 hours.

Producing alpha-alumina whiskers

The invention relates to producing relatively flaw free silicon nitride ceramic shapes requiring little or no machining by superplastic forging

Superplastic forging nitride ceramics

This invention relates to the production of improved high density nitrogen based ceramics by liquid-phase densification of silicon nitride or a compound of silicon-nitrogen-oxygen-metal, e.g. a sialon. In the process and compositions of the invention minor amounts of finely divided silicon are employed together with the conventional liquid phase producing additives to enhance the densification of the resultant ceramic.

Growing community of inventors

Ithaca, NY, United States of America

Rishi Raj