Gte Laboratories Incorporated

Boston University

Other

Gte Products Corporation

Alem Associates

Vinod K Sarin

Sergej-Tomislav V Buljan

Charles D'Angelo

Hans E Hintermann

Gilbert Gindraux

J Gary Baldoni, Ii

Jaime Sanchez

Helmut Lingertat

Robert A Penty

Peter Oberhauser

Stephen Gibson Topping

Sergei-Tomislav V Buljan

Shish P Arya

Helen E Rebenne

Charles Brecher

Deepak G Bhat

Daniel W Oblas

Paul F Woerner

Frank E Sivo

Joseph M Harris

Arun K Chaudhuri

Robert Rozbicki

Alex Lempicki

Rao Mulpuri

Transparent optical ceramic coating materials have been fabricated from europium-doped lutetium oxide (LuO:Eu) using physical vapor deposition and chemical vapor deposition techniques. The non-pixilated film coatings have columnar microcrystalline structure and excellent properties for use as radiological scintillators, namely very high density, high effective atomic number, and light output and emission wavelength suitable for use with silicon-based detectors having a very high quantum efficiency. The materials can be used in a multitude of high speed and high resolution imaging applications, including x-ray imaging in medicine.

Synthesis of advanced scintillators via vapor deposition techniques

This invention encompasses the oxides of lutetium and silicon in various proportions and containing a dopant, optionally cerium, fabricated in the form of a translucent ceramic, and methods of manufacture and use of such ceramic.

High-density polycrystalline lutetium silicate materials activated with Ce

A coated article for tribological applications, for example a cutting tool for machining titanium and its alloys. The densified substrate of the article is a cemented carbide, nitride, or carbonitride, or ceramic and may include cubic carbides. A composite coating is codeposited on the substrate to provide a wear surface including no cubic carbides to a depth at least sufficient to avoid exposure of cubic carbides to a workpiece during machining. The coating is a pore-free, dense, hard phase/cobalt composite applied by CVD or PVD, the hard phase including tungsten carbide, nitride, or carbonitride. The cutting tool thus possesses good shape retention at high machining speeds and provides wear-resistance and chemical inertness.

Abrasion resistant coated articles

This invention is directed to the creation of crystalline mullite coatings having uniform microstructure by chemical vapor deposition (CVD). The process comprises the steps of establishing a flow of reactants which will yield mullite in a CVD reactor, and depositing a crystalline coating from the reactant flow. The process will yield crystalline coatings which are dense and of uniform thickness.

Chemical vapor deposition of mullite coatings

This invention is directed to the creation of diamond coatings with enhanced adherence, nucleation density and uniformity on substrates. The method of this invention includes the formation of a carbide layer on a substrate surface prior to diamond coating deposition via a pretreatment stage using an unmodified oxy-acetylene combustion flame. The carbide layer may be formed at a temperature outside of the normal deposition temperature range and is treated as a separate step in the diamond growth process. The carbide layer serves to improve nucleation density, uniformity and adherence of the subsequent diamond coating. Many different types of substrates may benefit from the advantages of this invention.

Enhanced adherence of diamond coatings employing pretreatment process

This invention is directed to the creation of diamond coatings with enhanced adherence on substrates, such as tungsten carbide-cobalt (WC--Co), by chemical vapor deposition. This process comprises the steps of creating a combustion flame, supplying a deposition promoter to the flame, positioning a substrate into the flame, and forming the diamond deposit with enhanced adherence on the substrate. The invention is also directed to methods for the formation of a diamond deposit with enhanced adherence by the addition of a high-temperature binder such as a refractory metal or an organometallic compound. Once incorporated, the high-temperature binder acts as a cement which increase the strength and adhesion of the coating to the substrate.

Enhanced adherence of diamond coatings

This invention is directed to the creation of diamond coatings with enhanced adherence on substrates, such as tungsten carbide-cobalt (WC-Co), by chemical vapor deposition. This process comprises the steps of creating a combustion flame, supplying a deposition promoter to the flame, positioning a substrate into the flame, and forming the diamond deposit with enhanced adherence on the substrate. The invention is also directed to methods for the formation of a diamond deposit with enhanced adherence by the addition of a high-temperature binder such as a refractory metal or an organometallic compound. Once incorporated, the high-temperature binder acts as a cement which increase the strength and adhesion of the coating to the substrate.

Enhanced adherence of diamond coatings by combustion flame CVD

The invention provides pore-free, dense refractory metal binder composite and laminate coated articles including ceramic or cemented carbide substrates coated with refractory metal carbide, nitride, or carbonitride binder composite coatings. A tungsten carbide cobalt composite coated tungsten carbide cobalt article is provided. Refractory metal carbide, nitride and carbonitride binder composite layers and/or refractory metal carbide, nitride and carbonitride layers can be combined with binder layers to construct laminate coated articles. Among such laminate coated articles are structures which include at least one layer of tungsten carbide cobalt composite and at least one layer of cobalt on a tungsten carbide cobalt substrate.

A process for depositing a high temperature stress and oxidation resistant coating on a silicon nitride- or silicon carbide-based substrate body. A gas mixture is passed over the substrate at about 900.degree.-1500.degree. C. and about 1 torr to about ambient pressure. The gas mixture includes one or more halide vapors with other suitable reactant gases. The partial pressure ratios, flow rates, and process times are sufficient to deposit a continuous, fully dense, adherent coating. The halide and other reactant gases are gradually varied during deposition so that the coating is a graded coating of at least two layers. Each layer is a graded layer changing in composition from the material over which it is deposited to the material of the layer and further to the material, if any, deposited thereon, so that no clearly defined compositional interfaces exist. The gases and their partial pressures are varied according to a predetermined time schedule and the halide and other reactant gases are selected so that the layers include (a) an adherent, continuous intermediate layer about 0.5-20 microns thick of an aluminum nitride or an aluminum oxynitride material, over and chemically bonded to the substrate body, and (b) an adherent, continuous first outer layer about 0.5-900 microns thick including an oxide of aluminum or zirconium over and chemically bonded to the intermediate layer.

Process for the deposition of high temperature stress and oxidation

A microscratch-test method for measuring adhesion between a first material and a second material adhered to one another at an interface and forming an article. The method involves polishing a planar surface of the article generally normal to the interface and exposing the interface and the first and second materials. A static load of predetermined mass is applied to a starting point on the first or second material in a direction generally normal to the planar surface, using a load means of a third material harder than the first and second materials. The load means is moved across the planar surface from the starting point in a straight line generally toward and across the interface at an angle relative to the interface of between 90.degree. and about 20.degree.. These steps are repeated, varying the mass. The starting point for each repetition is spaced apart from other starting points but is approximately equidistant with other starting points from the interface. The lowest value of the predetermined mass is observed at which a predetermined level of damage to one or more of the interface, first material, and second material occurs. The scratch angle may be constant or may vary with each repetition.

Method for characterization of adhesion between hard materials

A wear resistant article, such as a cutting tool. A hard refractory substrate is coated with a composite refractory coating having at least two phases. The first phase is a continuous nitride matrix layer 0.1-20 microns thick of nitrides of Si, B, Al, Y, Ti, Zr, Hf, V, Nb, Ta, Mo, or W. At least one discontinuous second or additional phase of nitrides of Si, B, Al, Y, Ti, Zr, Hf, V, Nb, Ta, Mo, or W, or solid solutions thereof, is dispersed as discrete particles within the matrix layer. The additional phase material is different from the matrix material.

Composite coatings on refractory substrates

A chemical vapor deposition process in which an internal reactor is disposed within a chemical vapor deposition reactor including means for enclosing a reaction chamber and means for heating the reaction chamber. The position at which the internal reactor is disposed relative to the heating means is selected to provide control of the temperature within the internal reactor. At least two solid precursor materials are placed in the internal reactor and are contacted with at least one precursor gas, reactive with the solid precursor materials to produce at least two reactant gases. These gases are directed to the reaction chamber to react with one or more additional reactants.

Internal reactor method for chemical vapor deposition

An oxidation resistant, high temperature thermal cycling resistant coated ceramic article for ceramic heat engine applications. The substrate is a silicon-based material, i.e. a silicon nitride- or silicon carbide-based monolithic or composite material. The coating is a graded coating of at least two layers: an intermediate AlN or Al.sub.x N.sub.y O.sub.z layer and an aluminum oxide or zirconium oxide outer layer. The composition of the coating changes gradually from that of the substrate to that of the AlN or Al.sub.x N.sub.y O.sub.z layer and further to the composition of the aluminum oxide or zirconium oxide outer layer. Other layers may be deposited over the aluminum oxide layer. A CVD process for depositing the graded coating on the substrate is also disclosed.

Oxidation resistant high temperature thermal cycling resistant coatings

A co-deposition process for producing a wear resistant article, such as a cutting tool. Gaseous halides of two or more of Si, B, Al, Y, Ti, Zr, Hf, V, Nb, Ta, Mo, and W, with other reactants including a volatile nitrogen source, for example N.sub.2 or NH.sub.3, are passed over a hard refractory at a temperature above about 800.degree. C., and 1 torr to about ambient pressure to form a composite refactory coating layer on the substrate. The coating is a continuous first-phase nitride matrix having particles of at least one different nitride dispersed therein. Oxynitrides may be produced by including a volatile oxygen source, for example NO or NO.sub.2, in the gas mixture.

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Lexington, MA, United States of America

Vinod K Sarin