Process for the deposition of high temperature stress and oxidation resistant coatings on silicon-based substrates
A process is disclosed 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--1500 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.
- DOE Contract Number:
- AC05-84OR21400
- Assignee:
- GTE Laboratories Incorporated, Waltham, MA (United States)
- Patent Number(s):
- US 5035923; A
- Application Number:
- PPN: US 7-526365
- OSTI ID:
- 7175095
- Country of Publication:
- United States
- Language:
- English
Similar Records
Coated silicon nitride cutting tools
Oxidation resistant high temperature thermal cycling resistant coatings on silicon-based substrates and process for the production thereof
Related Subjects
360201* -- Ceramics
Cermets
& Refractories-- Preparation & Fabrication
ALUMINIUM COMPOUNDS
ALUMINIUM NITRIDES
ALUMINIUM OXIDES
CARBIDES
CARBON COMPOUNDS
CHALCOGENIDES
CHEMICAL COATING
CHEMICAL VAPOR DEPOSITION
COATINGS
DEPOSITION
HEAT RESISTANT MATERIALS
MATERIALS
NITRIDES
NITROGEN COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PNICTIDES
PROTECTIVE COATINGS
SILICON CARBIDES
SILICON COMPOUNDS
SILICON NITRIDES
SURFACE COATING
TRANSITION ELEMENT COMPOUNDS
ZIRCONIUM COMPOUNDS
ZIRCONIUM OXIDES