US20020028294A1 - Method for making a protective coating containing silicon carbide - Google Patents
Method for making a protective coating containing silicon carbide Download PDFInfo
- Publication number
- US20020028294A1 US20020028294A1 US09/354,681 US35468199A US2002028294A1 US 20020028294 A1 US20020028294 A1 US 20020028294A1 US 35468199 A US35468199 A US 35468199A US 2002028294 A1 US2002028294 A1 US 2002028294A1
- Authority
- US
- United States
- Prior art keywords
- silicon
- coating
- substrate
- carbon
- protective coating
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C26/00—Coating not provided for in groups C23C2/00 - C23C24/00
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/515—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics
- C04B35/56—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on carbides or oxycarbides
- C04B35/565—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on carbides or oxycarbides based on silicon carbide
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/71—Ceramic products containing macroscopic reinforcing agents
- C04B35/78—Ceramic products containing macroscopic reinforcing agents containing non-metallic materials
- C04B35/80—Fibres, filaments, whiskers, platelets, or the like
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B41/00—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone
- C04B41/45—Coating or impregnating, e.g. injection in masonry, partial coating of green or fired ceramics, organic coating compositions for adhering together two concrete elements
- C04B41/4505—Coating or impregnating, e.g. injection in masonry, partial coating of green or fired ceramics, organic coating compositions for adhering together two concrete elements characterised by the method of application
- C04B41/455—Coating or impregnating, e.g. injection in masonry, partial coating of green or fired ceramics, organic coating compositions for adhering together two concrete elements characterised by the method of application the coating or impregnating process including a chemical conversion or reaction
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B41/00—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone
- C04B41/45—Coating or impregnating, e.g. injection in masonry, partial coating of green or fired ceramics, organic coating compositions for adhering together two concrete elements
- C04B41/50—Coating or impregnating, e.g. injection in masonry, partial coating of green or fired ceramics, organic coating compositions for adhering together two concrete elements with inorganic materials
- C04B41/5053—Coating or impregnating, e.g. injection in masonry, partial coating of green or fired ceramics, organic coating compositions for adhering together two concrete elements with inorganic materials non-oxide ceramics
- C04B41/5057—Carbides
- C04B41/5059—Silicon carbide
Definitions
- the present invention relates to a method for making a protective coating containing silicon carbide, particularly a wear/tear, corrosion or abrasion protective coating on at least a portion of the surface of a substrate made from a material with a softening temperature that is above the melting temperature of silicon, where silicon is deposited on the portion of the surface of the substrate that is to be provided with a protective coating and where, under vacuum or in an inert atmosphere, the substrate is heated to a temperature above the melting point of silicon, brought to reaction with carbon that is contained in a porous coating, and, thereafter cooled down.
- Such a method is known from the German Patent No. DE-A1 42 03 773.
- the surface to be coated is initially covered with a coat of at least one meltable material and a binding agent, and prepared in such a manner, then is exposed to a heat treatment at a temperature above 600° C.
- This heat treatment occurs under vacuum or in an inert atmosphere.
- the coat is transformed to an at least partially porous top coating with an outer crust.
- the temperature is then increased such that the softening temperature of the object is not violated, however the meltable effective material is heated above its melting point.
- SiC coatings can be formed as protective coatings, where then Si powder and dust are applied to the object as a binding agent, a first heat treatment is performed at 700° C.-800° C. to carbonize the coat; thereafter, a heat treatment is carried out in a range of 1400° C. to 1700° C. for 1-2 hours to silicate the carbon structures. This creates an object with a SiC coating.
- a vehicle's brake disk, or clutch disk respectively is known from the German Utility Model No. DE-U1 296 10 498, where said disk is constructed of a C—C/SiC material, where the disk features an SiC coating.
- This SiC coating is formed by dip coating or made through vacuum impregnation.
- Thin protective coatings made of SiC that are used according to the above-mentioned current state-of-the-art are brittle even at room temperature. Due to this brittleness, cracking and chipping occur such that the desired effect of this coating as a protective coating is lost. This brittleness can be observed especially when the object covered with such a SiC coating is exposed to fluctuating temperature cycles.
- the surface of the object to be coated is initially provided with a porous carbon coating with a porosity in a range between 40 and 95%, and where said porous carbon coating is covered with coating of silicon, where the ratio of the mass of the applied silicon to that of the carbon in the porous carbon coating is greater than 2.34.
- the substrate is heated to a temperature that is above the melting temperature of the silicon, to a maximum temperature of 1650° C. to avoid a boiling condition of the silicon.
- the substrate, provided with the coating that contains silicon carbide and free silicon is cooled down to room temperature.
- porous carbon coating provides on the one hand the portion of carbon that will be brought to reaction with the silicon to form the subsequent protective coating containing the silicon carbide coating, and on the other hand, the rate of free silicon, that is important for the properties of the finished protective coating, can be set by selecting a porosity where a silicon surplus remains. Free silicon can then, on the one hand, be stored in the pores, and on the other hand, the rate of silicon can be set such that a thin coating that consists primarily of silicon remains on the surface of the finished protective coating.
- protective coatings that are formed according to the method subject to the invention are of particular advantage as wear/tear protective coatings on abrasion units such as brake disks, corrosion protective coatings on pipe-shaped heat exchanger elements or abrasion protective coatings on sliding ring packings.
- any substrate that has a temperature resistance to temperatures above the melting point of silicon can be coated with this coating.
- This includes ceramic substrates, substrates made of carbon, substrates made of silicon carbide, ceramic composite materials such as C/C, C/C—SiC, SiC/SiC, or metals such as tungsten, to name just the most important ones.
- Suitable for the structures of the porous carbon coating are carbon felt, carbon mats, carbon weaves, carbon foils and/or carbon fleece that are placed on the substrate according to the desired thickness of the protective coating.
- the porosity can be specified by selecting a suitable type of the aforementioned carbon materials.
- the carbon coating made of carbon felt or mats is preferable, because these materials have the advantage of a rapid and complete reaction between C and SiC, particularly when the individual fibers are very thin or in an amorphous condition.
- the porous carbon coating can be created through pyrolysis of paper, wood, wood pulp and/or cardboard placed on the substrate, where the pyrolysis of these materials occurs in the furnace during the heating stage prior to melting the creating the reaction with the carbon to form silicon carbide.
- the required silicon can be provided by applying particle-shaped silicon, where the particle size is to be between 0 and 15 mm.
- the coating thickness to be created is a particular criterion for selecting the particle size.
- the silicon can also be placed on the prepared porous carbon object in the shape of a plate made of silicon. Such a plate material has the advantage that uniform coverage of the C-coating is possible for flat objects.
- the silicon to be used should have a purity of 99.9% to prevent the protective coating from being contaminated, or to ensure that the protective coating to be created basically contains only silicon carbide and free silicon. It has been found that in order to achieve the advantages of the protective coating subject to the invention as described above, the ratio of percent mass (Ma-%) of applied silicon to carbon should be in a range of 2.35 to 49.
- a high set value for the portion of free silicon in the protective coating is preferred, that is, the free silicon should be 50% to 90% in relation to the total mass, preferably 70% to 90%, where in the latter range a value of 90% is preferred.
- the result of such a high content of free silicon is that the protective coating is less brittle, and thus has no tendency to chip (under thermal and/or mechanical load) after cooling down to room temperature.
- the substrate is preferably made of carbon, a composite of carbon/fiber-enforced carbon, C—SiC, C/C—SiC, or of SiC—SiC to achieve a homogenous structure with high strength, where this object features the advantages of the applied protective coating listed above.
- the substrate consists of a material of the same type, that is, it consists of carbon and silicon carbide.
- a C/C—SiC object is made of C fibers with a C+SiC matrix, for example, which does not require subsequent condensing, according to the LSI method.
- a SiC—SiC object is made of SiC fibers with a SiC matrix according to the CVI method, an always porous object with a surface that should, therefore, possibly be condensed prior to applying the protective coating.
- a protective coating with a thickness of 0.2 to 2 mm is sufficient for achieving the desired advantages.
- a protective coating is selected which is too thin, the protective effect will be lost due to unavoidable abrasion, etc. during use.
- the effect of values above 2 mm is that the tendency for chipping increases due to tension cracking. In general, the tendency for chipping is proportional to the coating thickness.
- Heating rates that are basically uniform should be observed during heat treatment to build a homogenous coating, that is, to achieve, or ensure, a complete reaction of the available carbon with the silicon to form silicon carbide.
- the substrate with the applied prepared carbon coating and the silicon coating applied on top should be heated to a temperature of about 1420° C.
- the temperature should then be raised to between 1420 and 1650° C. After that, the temperature should be kept at that level for a period of 1 to 60 minutes.
- the holding time depends on the temperature and the thickness. For thin coatings (0.2 mm), a short holding time (1 min) is sufficient; for thick coatings (2 mm) a holding time of up to 60 min is required.
- the object provided with the protective coating should be cooled to room temperature at a uniform cooling rate. It has been found that surface cracks or tension cracks can occur during this cool down period. These cracks are undesired and are the result of the decrease in tension between the coating and the substrate material due to an a maladjustment. These tension cracks can be kept to a minimum when the thermal expansion of coating and substrate material is of a similar magnitude.
- Heating of the substrate to a temperature of 1420° C. should occur at a heating rate in a range of 40 to 400 K/h, preferably of 40 to 200 K/h, and particularly of 80 K/h, which is a compromise between process duration and uniform heating of the components and the coating to be created.
- the cool down rate should then, after the silicon has been brought to reaction with the carbon, be in a range of 20 to 200 K/h, preferably at about 70 K/h.
- a cool down rate of 70 K/h will ensure that cracks can occur successively in the coating.
- the internal pressure in the furnace, where the heat treatment is being performed should be kept at about 10 ⁇ 3 -10 ⁇ 6 bar. This internal pressure ensures that the melting point of silicon, that of about 1420° C. is reached, so that oxidation is prevented and that a rapid conversion of silicon and carbon to silicon carbide occurs.
- FIGS. 1A to 1 C show schematically the process steps to create a protective coating on a substrate according to the method subject to the invention.
- FIG. 2 shows an electron microscope image of the protective coating with a 200 ⁇ magnification.
- FIG. 3 shows the cross-section of an arrangement for applying the protective coating on the outside of a pipe.
- FIG. 4 shows the cross-section of an arrangement for applying the protective coating on the inside of a pipe.
- FIGS. 1 - 4 of the drawings Identical elements in the various figures are identified by the same reference numerals.
- a substrate 1 for example a fiber-enforced ceramic disk (C/C—SiC substrate disk) is initially ground flat using a diamond disk with a grain of 150.
- the substrate 1 is then covered with a 2 mm thick carbon fleece 2 , consisting of 15 individual layers with a thickness of 0.13 mm and an area weight of 30 g/m 2 .
- This carbon fleece 2 has a mass of 19.6 g relative to the area to be coated, e.g., an abrasion surface and is uniformly covered with 12.5 times the weight in silicon 3 , that is, with a total of 245 g of silicon (purity 99.9% and grain size 0-15 mm), as shown in FIG. 1A.
- heating occurs in a vacuum furnace at an internal pressure of 10 ⁇ 6 bar with a heating rate of 40 K/h, initially to a temperature of 1650° C. (FIG. 1B).
- the silicon 3 begins to melt at 1420° C. and the carbon fleece infiltrates as is indicated by the arrows 4 in FIG. 1B.
- the reaction with the carbon occurs at a temperature between 1420° C. and 1650° C. such that silicon carbide 5 is formed. Due to the amount of silicon 3 that has been applied to the carbon fleece coating, silicon has been provided in a stoichiometric surplus in relation to the carbon, with residue of free silicon remains after the heat treatment, as indicated in FIG.
- silicon carbide (SiC) is present with about 20% mass portion in relation to the protective coating 5 consisting of Si and SiC while free silicon is present in an amount of 80% in relation to the total mass Si and SiC.
- the distribution of the free silicon 3 that infiltrates the silicon carbide 5 can be adjusted through the type of carbon fleece used, that is, through its porosity.
- the object is cooled down, preferably at a cool down rate of 70 K/h with the unit remaining in the furnace at the aforementioned internal pressure of the furnace.
- a cool down rate of 70 K/h with the unit remaining in the furnace at the aforementioned internal pressure of the furnace.
- small tension cracks may occur. Such tension cracks are tolerable.
- the finished substrate 1 coated with the protective coating 6 , has a structure in the transition phase between substrate 1 and protective coating 6 when viewed with an electron microscope as shown in FIG. 2.
- the light gray areas represent free silicon 3
- the dark gray areas 6 represent SiC
- the black areas 7 represent carbon in the substrate 1 (fibers and matrix).
- the portion of free silicon 3 in the protective coating 6 which is about 80%, is in relation to the mass of this protective coating 6 . Because FIG. 2 only shows a small section of the transition phase between substrate 1 and protective coating 6 , a part of the protective coating potentially remaining on the outside and containing the free silicon, as shown schematically in FIG. 3C, cannot be seen.
- the portion of free Si in the protective coating 6 provides a strong bond with the substrate to be coated.
- the toughness and elasticity of the protective coating 6 can be adjusted using the amount of free Si, with both toughness and elasticity being improved by the portion of free Si compared to a pure SiC coating.
- Coating 6 is dense, that is, it hardly has pores due to the fact that silicon exhibits an increase in volume when congealing, so that shrinkage pores do not occur, but only tension cracks occur during the continued cool down to room temperature when the heat expansion of the coating 6 and of the substrate material 1 is different.
- the increase in fracture toughness of the coating can be explained in that silicon has a Mohs hardness of 7 while the hardness of SiC is between 9.5 and 9.75.
- silicon has a higher temperature fluctuation resistance due to its lower heat expansion coefficient of 2.6*10 ⁇ 6 K ⁇ 1 in comparison to silicon carbide (with a heat expansion coefficient of 4.7*10 ⁇ 6 K ⁇ 1 ), which increases the overall temperature fluctuation resistance of the protective coating as well. This, in turn, increases the bonding properties of an abrasion coating of a brake disk.
- FIG. 3 Another example for an advantageous application of the method subject to the invention is the sheathing of a pipe-shaped substrate 8 with such a protective coating.
- a C/C—SiC pipe 8 that is to be provided with a protective coating on the outside is wrapped with seven layers of carbon fleece 2 (area weight 30 g/m 2 ).
- a graphite trough is provided that corresponds to the final contours of the pipe.
- pipe 8 that is to be coated is surrounded on all sides with Si granules, is then placed into this trough, or a graphite crucible 9 , and then heat-treated as described above using FIGS. 1A to 1 B. During the heat treatment at 1650° C.
- the Si granules 3 are brought to reaction with the carbon of the carbon fleece 2 , such that a structure is created like the one presented in FIG. 1C. This is followed by a cool down to room temperature. In this manner, such pipes 8 can be covered with an outer protective coating.
- a pipe-shaped object shall be coated on the inside.
- a pipe 8 made of C/C—SiC is provided and lined with seven layers of carbon fleece (area weight 30 g/m 2 ), as can be seen in FIG. 4.
- a graphite core 10 is then inserted into this inner space.
- pipe 10 is placed upright into a vacuum furnace and provided with a funnel-like device serving as a storage container for the silicon 3 .
- Heat treatment is carried out in the same manner as the coating of the outside of the pipe.
- the molten silicon flows into the porous carbon object and reacts with the carbon to form SiC.
- the portion of free silicon is adjusted by the surplus of silicon placed in funnel 11 .
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Ceramic Engineering (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Structural Engineering (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Manufacturing & Machinery (AREA)
- Inorganic Chemistry (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Ceramic Products (AREA)
Abstract
Description
- The present invention relates to a method for making a protective coating containing silicon carbide, particularly a wear/tear, corrosion or abrasion protective coating on at least a portion of the surface of a substrate made from a material with a softening temperature that is above the melting temperature of silicon, where silicon is deposited on the portion of the surface of the substrate that is to be provided with a protective coating and where, under vacuum or in an inert atmosphere, the substrate is heated to a temperature above the melting point of silicon, brought to reaction with carbon that is contained in a porous coating, and, thereafter cooled down.
- Such a method is known from the German Patent No. DE-A1 42 03 773. According to the method known from this, to heat-treat the surface of an object, the surface to be coated is initially covered with a coat of at least one meltable material and a binding agent, and prepared in such a manner, then is exposed to a heat treatment at a temperature above 600° C. This heat treatment occurs under vacuum or in an inert atmosphere. During this process, the coat is transformed to an at least partially porous top coating with an outer crust. The temperature is then increased such that the softening temperature of the object is not violated, however the meltable effective material is heated above its melting point. This increased temperature is then maintained until the melted effective material is at least partially vaporized and in the process by diffusion has created a surface zone that forms a dense coating in the surface material of the object together with this surface material. Thereafter, the top coating is cooled down and removed from the object. With such a method, SiC coatings can be formed as protective coatings, where then Si powder and dust are applied to the object as a binding agent, a first heat treatment is performed at 700° C.-800° C. to carbonize the coat; thereafter, a heat treatment is carried out in a range of 1400° C. to 1700° C. for 1-2 hours to silicate the carbon structures. This creates an object with a SiC coating.
- In addition, a vehicle's brake disk, or clutch disk respectively, is known from the German Utility Model No. DE-U1 296 10 498, where said disk is constructed of a C—C/SiC material, where the disk features an SiC coating. This SiC coating is formed by dip coating or made through vacuum impregnation.
- Thin protective coatings made of SiC that are used according to the above-mentioned current state-of-the-art are brittle even at room temperature. Due to this brittleness, cracking and chipping occur such that the desired effect of this coating as a protective coating is lost. This brittleness can be observed especially when the object covered with such a SiC coating is exposed to fluctuating temperature cycles.
- Based on this state-of-the-art, it is the objective of the present invention to cover an object with a protective coating that features the advantages of an SiC coating, which however, does not have the brittleness that is present with coatings according to the current state-of-the-art.
- With the type of method referred to at the beginning, this objective is accomplished, that in order to achieve a homogeneous protective coating of silicon carbide and free silicon, the surface of the object to be coated is initially provided with a porous carbon coating with a porosity in a range between 40 and 95%, and where said porous carbon coating is covered with coating of silicon, where the ratio of the mass of the applied silicon to that of the carbon in the porous carbon coating is greater than 2.34. The substrate is heated to a temperature that is above the melting temperature of the silicon, to a maximum temperature of 1650° C. to avoid a boiling condition of the silicon. The substrate, provided with the coating that contains silicon carbide and free silicon, is cooled down to room temperature.
- To form the coating subject to the invention, it is initially important to provide a porous carbon coating on the substrate to be coated. This porous carbon coating provides on the one hand the portion of carbon that will be brought to reaction with the silicon to form the subsequent protective coating containing the silicon carbide coating, and on the other hand, the rate of free silicon, that is important for the properties of the finished protective coating, can be set by selecting a porosity where a silicon surplus remains. Free silicon can then, on the one hand, be stored in the pores, and on the other hand, the rate of silicon can be set such that a thin coating that consists primarily of silicon remains on the surface of the finished protective coating. In any case, attention has to be paid to the fact that the applied silicon in relation to the carbon in the porous carbon coating, concerning the ratio of silicon to carbon in percent of mass is greater than 2.34. The structure of such a protective coating does not require organic binding agents that would otherwise compromise the purity or quality of the silicon through splitting off of decomposition products during the heating phase or through outgasing.
- It has been found, that practically no wear occurs when using such a surface protective coating that contains a portion of free silicon, when such an object coated with such a surface coating is brought into abrasive contact with an organic layer, for example, with organic abrasive coatings of an abrasion unit. In addition, such a coating distinguishes itself through a very high thermal shock resistance, that is, R1≧500 K, where R1 is defined as the ratio of the tensile stress (σ) to E * α, where E is the modulus of elasticity and α the coefficient of thermal expansion of the protective coating.
- To name a few preferred areas of applications, protective coatings that are formed according to the method subject to the invention are of particular advantage as wear/tear protective coatings on abrasion units such as brake disks, corrosion protective coatings on pipe-shaped heat exchanger elements or abrasion protective coatings on sliding ring packings.
- It is apparent that such protective coatings do not require that the object that is to be coated exhibits a certain porosity, because the protective coating is applied to the object to be coated by using a porous carbon object or a porous carbon coating respectively. To enhance bonding between the substrate and the protective coating, it may be advantageous to adjust the roughness of the surface of the substrate to be coated, for example to a mean roughness of Ra=2. Precisely such a roughness value offers the advantage of a uniform and strong bond between the protective coating and the substrate.
- Practically any substrate that has a temperature resistance to temperatures above the melting point of silicon can be coated with this coating. This includes ceramic substrates, substrates made of carbon, substrates made of silicon carbide, ceramic composite materials such as C/C, C/C—SiC, SiC/SiC, or metals such as tungsten, to name just the most important ones.
- Suitable for the structures of the porous carbon coating are carbon felt, carbon mats, carbon weaves, carbon foils and/or carbon fleece that are placed on the substrate according to the desired thickness of the protective coating. The porosity can be specified by selecting a suitable type of the aforementioned carbon materials. The carbon coating made of carbon felt or mats is preferable, because these materials have the advantage of a rapid and complete reaction between C and SiC, particularly when the individual fibers are very thin or in an amorphous condition. Alternatively, the porous carbon coating can be created through pyrolysis of paper, wood, wood pulp and/or cardboard placed on the substrate, where the pyrolysis of these materials occurs in the furnace during the heating stage prior to melting the creating the reaction with the carbon to form silicon carbide.
- The required silicon can be provided by applying particle-shaped silicon, where the particle size is to be between 0 and 15 mm. The coating thickness to be created is a particular criterion for selecting the particle size. The silicon can also be placed on the prepared porous carbon object in the shape of a plate made of silicon. Such a plate material has the advantage that uniform coverage of the C-coating is possible for flat objects.
- The silicon to be used should have a purity of 99.9% to prevent the protective coating from being contaminated, or to ensure that the protective coating to be created basically contains only silicon carbide and free silicon. It has been found that in order to achieve the advantages of the protective coating subject to the invention as described above, the ratio of percent mass (Ma-%) of applied silicon to carbon should be in a range of 2.35 to 49. A high set value for the portion of free silicon in the protective coating is preferred, that is, the free silicon should be 50% to 90% in relation to the total mass, preferably 70% to 90%, where in the latter range a value of 90% is preferred. The result of such a high content of free silicon is that the protective coating is less brittle, and thus has no tendency to chip (under thermal and/or mechanical load) after cooling down to room temperature.
- The substrate is preferably made of carbon, a composite of carbon/fiber-enforced carbon, C—SiC, C/C—SiC, or of SiC—SiC to achieve a homogenous structure with high strength, where this object features the advantages of the applied protective coating listed above. With reference to the applied coating, the substrate consists of a material of the same type, that is, it consists of carbon and silicon carbide.
- A C—SiC object is made of C fibers with a relatively porous SiC matrix using, for example, the CVI method or the LPI method (CVI=Chemical Vapor Infiltration, LPI=Liquid Polymer Infiltration).
- A C/C—SiC object is made of C fibers with a C+SiC matrix, for example, which does not require subsequent condensing, according to the LSI method.
- A SiC—SiC object is made of SiC fibers with a SiC matrix according to the CVI method, an always porous object with a surface that should, therefore, possibly be condensed prior to applying the protective coating.
- A protective coating with a thickness of 0.2 to 2 mm is sufficient for achieving the desired advantages. When a protective coating is selected which is too thin, the protective effect will be lost due to unavoidable abrasion, etc. during use. The effect of values above 2 mm is that the tendency for chipping increases due to tension cracking. In general, the tendency for chipping is proportional to the coating thickness.
- Heating rates that are basically uniform should be observed during heat treatment to build a homogenous coating, that is, to achieve, or ensure, a complete reaction of the available carbon with the silicon to form silicon carbide. Initially, the substrate with the applied prepared carbon coating and the silicon coating applied on top should be heated to a temperature of about 1420° C. The temperature should then be raised to between 1420 and 1650° C. After that, the temperature should be kept at that level for a period of 1 to 60 minutes. Basically, the holding time depends on the temperature and the thickness. For thin coatings (0.2 mm), a short holding time (1 min) is sufficient; for thick coatings (2 mm) a holding time of up to 60 min is required. A prerequisite is sufficient porosity that allows the silicon to react with the entire carbon during this holding time. Thereafter, the object provided with the protective coating should be cooled to room temperature at a uniform cooling rate. It has been found that surface cracks or tension cracks can occur during this cool down period. These cracks are undesired and are the result of the decrease in tension between the coating and the substrate material due to an a maladjustment. These tension cracks can be kept to a minimum when the thermal expansion of coating and substrate material is of a similar magnitude.
- Heating of the substrate to a temperature of 1420° C. should occur at a heating rate in a range of 40 to 400 K/h, preferably of 40 to 200 K/h, and particularly of 80 K/h, which is a compromise between process duration and uniform heating of the components and the coating to be created. The cool down rate should then, after the silicon has been brought to reaction with the carbon, be in a range of 20 to 200 K/h, preferably at about 70 K/h. A cool down rate of 70 K/h will ensure that cracks can occur successively in the coating. The internal pressure in the furnace, where the heat treatment is being performed, should be kept at about 10−3-10−6 bar. This internal pressure ensures that the melting point of silicon, that of about 1420° C. is reached, so that oxidation is prevented and that a rapid conversion of silicon and carbon to silicon carbide occurs.
- For a full understanding of the present invention, reference should now be made to the following detailed description of the preferred embodiments of the invention as illustrated in the accompanying drawings.
- FIGS. 1A to1C show schematically the process steps to create a protective coating on a substrate according to the method subject to the invention.
- FIG. 2 shows an electron microscope image of the protective coating with a 200×magnification.
- FIG. 3 shows the cross-section of an arrangement for applying the protective coating on the outside of a pipe.
- FIG. 4 shows the cross-section of an arrangement for applying the protective coating on the inside of a pipe.
- The present invention will now be described with reference to FIGS.1-4 of the drawings. Identical elements in the various figures are identified by the same reference numerals.
- To provide the surface of an object with a protective coating of the type subject to the invention, a
substrate 1, for example a fiber-enforced ceramic disk (C/C—SiC substrate disk) is initially ground flat using a diamond disk with a grain of 150. To build up a 2 mm thick coating as protective coating, thesubstrate 1 is then covered with a 2 mmthick carbon fleece 2, consisting of 15 individual layers with a thickness of 0.13 mm and an area weight of 30 g/m2. Thiscarbon fleece 2 has a mass of 19.6 g relative to the area to be coated, e.g., an abrasion surface and is uniformly covered with 12.5 times the weight insilicon 3, that is, with a total of 245 g of silicon (purity 99.9% and grain size 0-15 mm), as shown in FIG. 1A. - Next, heating occurs in a vacuum furnace at an internal pressure of 10−6 bar with a heating rate of 40 K/h, initially to a temperature of 1650° C. (FIG. 1B). The
silicon 3 begins to melt at 1420° C. and the carbon fleece infiltrates as is indicated by thearrows 4 in FIG. 1B. The reaction with the carbon occurs at a temperature between 1420° C. and 1650° C. such thatsilicon carbide 5 is formed. Due to the amount ofsilicon 3 that has been applied to the carbon fleece coating, silicon has been provided in a stoichiometric surplus in relation to the carbon, with residue of free silicon remains after the heat treatment, as indicated in FIG. 1C, both of which are embedded in thesilicon carbide 5 and as an outer coating. Based on the initial amounts of carbon and silicon described above, silicon carbide (SiC) is present with about 20% mass portion in relation to theprotective coating 5 consisting of Si and SiC while free silicon is present in an amount of 80% in relation to the total mass Si and SiC. The distribution of thefree silicon 3 that infiltrates thesilicon carbide 5 can be adjusted through the type of carbon fleece used, that is, through its porosity. - After the end of the heat treatment at 1650° C., the object is cooled down, preferably at a cool down rate of 70 K/h with the unit remaining in the furnace at the aforementioned internal pressure of the furnace. During the cool down phase, small tension cracks may occur. Such tension cracks are tolerable.
- The
finished substrate 1, coated with theprotective coating 6, has a structure in the transition phase betweensubstrate 1 andprotective coating 6 when viewed with an electron microscope as shown in FIG. 2. The light gray areas representfree silicon 3, the darkgray areas 6 represent SiC and theblack areas 7 represent carbon in the substrate 1 (fibers and matrix). The portion offree silicon 3 in theprotective coating 6 which is about 80%, is in relation to the mass of thisprotective coating 6. Because FIG. 2 only shows a small section of the transition phase betweensubstrate 1 andprotective coating 6, a part of the protective coating potentially remaining on the outside and containing the free silicon, as shown schematically in FIG. 3C, cannot be seen. - The advantage of the
protective coating 6 as described above, can be seen in its good bonding properties, even on orthotropic substrates. It has a very high hardness, with nevertheless a remaining elasticity. It can be manufactured at a reasonable expense, it is dense and forms a non-porous coating due to the anomaly of silicon. - The portion of free Si in the
protective coating 6 provides a strong bond with the substrate to be coated. In addition, the toughness and elasticity of theprotective coating 6 can be adjusted using the amount of free Si, with both toughness and elasticity being improved by the portion of free Si compared to a pure SiC coating.Coating 6 is dense, that is, it hardly has pores due to the fact that silicon exhibits an increase in volume when congealing, so that shrinkage pores do not occur, but only tension cracks occur during the continued cool down to room temperature when the heat expansion of thecoating 6 and of thesubstrate material 1 is different. The increase in fracture toughness of the coating can be explained in that silicon has a Mohs hardness of 7 while the hardness of SiC is between 9.5 and 9.75. This is also the reason for the low brittleness of the coating. In addition, silicon has a higher temperature fluctuation resistance due to its lower heat expansion coefficient of 2.6*10−6 K−1 in comparison to silicon carbide (with a heat expansion coefficient of 4.7*10−6 K−1), which increases the overall temperature fluctuation resistance of the protective coating as well. This, in turn, increases the bonding properties of an abrasion coating of a brake disk. - Another example for an advantageous application of the method subject to the invention is the sheathing of a pipe-shaped substrate8 with such a protective coating. To this end, as shown in FIG. 3, for example, a C/C—SiC pipe 8 that is to be provided with a protective coating on the outside is wrapped with seven layers of carbon fleece 2 (area weight 30 g/m2). A graphite trough is provided that corresponds to the final contours of the pipe. Thereafter, pipe 8, that is to be coated is surrounded on all sides with Si granules, is then placed into this trough, or a graphite crucible 9, and then heat-treated as described above using FIGS. 1A to 1B. During the heat treatment at 1650° C. for up to 1 hour, the
Si granules 3 are brought to reaction with the carbon of thecarbon fleece 2, such that a structure is created like the one presented in FIG. 1C. This is followed by a cool down to room temperature. In this manner, such pipes 8 can be covered with an outer protective coating. - The following method can be used if, for example, a pipe-shaped object shall be coated on the inside. For example, a pipe8 made of C/C—SiC is provided and lined with seven layers of carbon fleece (area weight 30 g/m2), as can be seen in FIG. 4. A graphite core 10 is then inserted into this inner space. For silicating, pipe 10 is placed upright into a vacuum furnace and provided with a funnel-like device serving as a storage container for the
silicon 3. Heat treatment is carried out in the same manner as the coating of the outside of the pipe. The molten silicon flows into the porous carbon object and reacts with the carbon to form SiC. The portion of free silicon is adjusted by the surplus of silicon placed in funnel 11. - From the above mentioned examples, it is apparent that complicated structures that are to be covered with a protective coating of a specified thickness containing silicon carbide can be made in this manner as well.
- There has thus been shown and described a novel method for making a protective coating containing silicon carbide which fulfills all the objects and advantages sought therefor. Many changes, modifications, variations and other uses and applications of the subject invention will, however, become apparent to those skilled in the art after considering this specification and the accompanying drawings which disclose the preferred embodiments thereof. All such changes, modifications, variations and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention, which is to be limited only by the claims which follow.
Claims (24)
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE19834018A DE19834018C1 (en) | 1998-07-28 | 1998-07-28 | Method for producing a protective layer containing silicon carbide |
DE19834018 | 1998-07-28 | ||
DE19834018.4 | 1998-07-28 |
Publications (2)
Publication Number | Publication Date |
---|---|
US20020028294A1 true US20020028294A1 (en) | 2002-03-07 |
US6358565B1 US6358565B1 (en) | 2002-03-19 |
Family
ID=7875620
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/354,681 Expired - Lifetime US6358565B1 (en) | 1998-07-28 | 1999-07-16 | Method for making a protective coating containing silicon carbide |
Country Status (3)
Country | Link |
---|---|
US (1) | US6358565B1 (en) |
EP (1) | EP0976698B1 (en) |
DE (2) | DE19834018C1 (en) |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20020084558A1 (en) * | 1999-02-09 | 2002-07-04 | Ngk Insulators, Ltd. | SiC-C/C composite material, uses thereof, and method for producing the same |
US20020179225A1 (en) * | 2000-03-24 | 2002-12-05 | Thomas Behr | Fiber-reinforced structural component |
EP1380809A2 (en) * | 2002-07-10 | 2004-01-14 | Sgl Carbon Ag | Ceramic composite bodies |
US20060062984A1 (en) * | 2002-07-04 | 2006-03-23 | Bodo Benitsch | Multilayer composite |
US20140323636A1 (en) * | 2011-12-13 | 2014-10-30 | Lg Hausys, Ltd. | Synthetic marble with high hardness and method of manufacturing the same |
GB2582379A (en) * | 2019-03-22 | 2020-09-23 | Tenmat Ltd | Method of coating carbon components |
RU2822187C1 (en) * | 2023-12-19 | 2024-07-03 | Акционерное общество "Уральский научно-исследовательский институт композиционных материалов" | Methods of making sealed articles from composite materials (versions) and housing of high-temperature chemical reactor made by these methods |
Families Citing this family (40)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6673198B1 (en) * | 1999-12-22 | 2004-01-06 | Lam Research Corporation | Semiconductor processing equipment having improved process drift control |
US20030035901A1 (en) * | 2001-08-17 | 2003-02-20 | Eiji Tani | Silicon carbide-based, porous, lightweight, heat-resistant structural material and manufacturing method therefor |
DE10056102A1 (en) * | 2000-11-13 | 2002-06-06 | Freudenberg Carl Kg | Mechanical seal |
DE10131769C5 (en) * | 2001-06-30 | 2010-02-18 | Audi Ag | Brake system with composite brake disc |
DE60233906D1 (en) * | 2001-12-25 | 2009-11-12 | Jtekt Corp | coupling device |
JP3961879B2 (en) * | 2002-05-24 | 2007-08-22 | 株式会社豊田中央研究所 | Friction clutch and driving force transmission device |
KR100520436B1 (en) * | 2003-01-30 | 2005-10-11 | 한국과학기술원 | Method for Making Oxidation Protective Double Coating for Carbon/Carbon Composite |
KR100520435B1 (en) * | 2003-01-30 | 2005-10-11 | 한국과학기술원 | Method for Making Oxidation Protective Coating for Carbon/Carbon Composite |
DE10320183B4 (en) * | 2003-05-02 | 2011-06-22 | Köthener Spezialdichtungen GmbH, 06369 | Production of wear-resistant and break-proof seal rings for mechanical seals |
JP3938558B2 (en) * | 2003-05-13 | 2007-06-27 | 本田技研工業株式会社 | Brake disc manufacturing method |
DE20311346U1 (en) * | 2003-07-23 | 2003-10-02 | Burgmann Dichtungswerke Gmbh | For a common rotation with an engine shaft designed sliding ring of a mechanical seal arrangement for jet engines |
DE10348123C5 (en) * | 2003-10-16 | 2007-10-31 | Daimlerchrysler Ag | Process for producing a silicon carbide ceramic component |
KR100627888B1 (en) * | 2004-05-25 | 2006-09-25 | 도시바세라믹스가부시키가이샤 | A substrate for growth of chemical compound semiconductor, a chemical compound semiconductor using the substrate and a process for producing them |
US7501181B2 (en) * | 2006-03-17 | 2009-03-10 | Honeywell International Inc. | Bi-or tri-layer anti-oxidation system for carbon composite brakes |
DE102007010675B4 (en) * | 2007-03-02 | 2009-04-23 | Astrium Gmbh | Method for producing a component made of a fiber-reinforced ceramic, component produced thereafter and its use as an engine component |
RU2484013C2 (en) * | 2011-02-08 | 2013-06-10 | Бушуев Вячеслав Максимович | Method of making articles from composite material |
RU2468991C1 (en) * | 2011-04-05 | 2012-12-10 | Вячеслав Максимович Бушуев | Method of manufacturing products from carbon-silicon material |
US9663374B2 (en) | 2011-04-21 | 2017-05-30 | The United States Of America, As Represented By The Secretary Of The Navy | Situ grown SiC coatings on carbon materials |
RU2486132C2 (en) * | 2011-06-27 | 2013-06-27 | Вячеслав Максимович Бушуев | Method of making articles from carbon-silicon carbide material |
RU2470857C1 (en) * | 2011-07-18 | 2012-12-27 | Государственное образовательное учреждение высшего профессионального образования "Пермский государственный технический университет" | Method of making parts from carbon-carbide-silicon material |
RU2469950C1 (en) * | 2011-07-26 | 2012-12-20 | Государственное образовательное учреждение высшего профессионального образования "Пермский государственный технический университет" | Method of manufacturing products from carbon-silicon carbide material |
DE102012218961A1 (en) * | 2012-10-17 | 2014-04-30 | Sgl Carbon Se | Ceramic dewatering element formed in one piece, useful for a machine for producing a fibrous web, preferably a paper-, cardboard- or packaging paper web, comprises a ceramic carrier and a support for the ceramic carrier |
US9051882B2 (en) | 2013-03-15 | 2015-06-09 | Rolls-Royce Corporation | Seals for a gas turbine engine |
DE102013216437A1 (en) * | 2013-08-20 | 2015-02-26 | Voith Patent Gmbh | Use of fiber-ceramic composites in the paper machine |
US9440287B2 (en) * | 2014-08-15 | 2016-09-13 | Siemens Energy, Inc. | Coatings for high temperature components |
US20160230570A1 (en) | 2015-02-11 | 2016-08-11 | Rolls-Royce High Temperature Composites Inc. | Modified atmosphere melt infiltration |
US9944526B2 (en) | 2015-05-13 | 2018-04-17 | Honeywell International Inc. | Carbon fiber preforms |
US10302163B2 (en) | 2015-05-13 | 2019-05-28 | Honeywell International Inc. | Carbon-carbon composite component with antioxidant coating |
US10131113B2 (en) | 2015-05-13 | 2018-11-20 | Honeywell International Inc. | Multilayered carbon-carbon composite |
US10465534B2 (en) * | 2015-06-05 | 2019-11-05 | Rolls-Royce North American Technologies, Inc. | Machinable CMC insert |
US10472976B2 (en) * | 2015-06-05 | 2019-11-12 | Rolls-Royce Corporation | Machinable CMC insert |
US10458653B2 (en) * | 2015-06-05 | 2019-10-29 | Rolls-Royce Corporation | Machinable CMC insert |
US10035305B2 (en) | 2015-06-30 | 2018-07-31 | Honeywell International Inc. | Method of making carbon fiber preforms |
US10022890B2 (en) | 2015-09-15 | 2018-07-17 | Honeywell International Inc. | In situ carbonization of a resin to form a carbon-carbon composite |
US10300631B2 (en) | 2015-11-30 | 2019-05-28 | Honeywell International Inc. | Carbon fiber preforms |
RU2613220C1 (en) * | 2015-12-25 | 2017-03-15 | Акционерное общество "Научно-исследовательский институт конструкционных материалов на основе графита "НИИграфит" | Method of producing protective coatings on materials and articles with carbon-containing base for exploitation in high velocity oxidant streams |
DE102016216882B4 (en) * | 2016-09-06 | 2020-06-18 | Hawe Hydraulik Se | Method of manufacturing a hydraulic component and hydraulic component |
CN112110741B (en) * | 2020-08-28 | 2022-04-22 | 湖南东映碳材料科技有限公司 | Preparation method of high-thermal-conductivity C/C-SiC composite material |
CN112110739B (en) * | 2020-08-28 | 2022-04-22 | 湖南东映碳材料科技有限公司 | Preparation method of three-dimensional high-thermal-conductivity C/C-ZrC-SiC composite material |
CN113053547A (en) * | 2021-03-10 | 2021-06-29 | 华北电力大学 | Multi-scale structure coating for enhancing boiling heat exchange and preparation method thereof |
Family Cites Families (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CA1081558A (en) * | 1975-10-24 | 1980-07-15 | Joseph D. Heaps | Method for dip-coating ceramic with molten silicon |
US5518816A (en) * | 1981-04-08 | 1996-05-21 | Loral Vought Systems Corporation | Composition and method for forming a protective coating on carbon-carbon chemical vapor deposition densified substrates |
DE3426911A1 (en) * | 1984-07-20 | 1986-01-30 | United Technologies Corp., Hartford, Conn. | Composite carbon-carbon article of high resistance to degradation by environmental action at elevated temperatures |
JP2579563B2 (en) * | 1991-04-26 | 1997-02-05 | 東海カーボン株式会社 | Oxidation-resistant treatment of carbon fiber reinforced carbon composites. |
JP2607409B2 (en) * | 1991-11-11 | 1997-05-07 | 東海カーボン株式会社 | Oxidation-resistant treatment of carbon fiber reinforced carbon composites. |
DE4203773A1 (en) * | 1992-02-10 | 1993-08-12 | Huels Chemische Werke Ag | METHOD FOR COATING THE SURFACE OF A BODY |
US5205970A (en) * | 1992-04-03 | 1993-04-27 | General Electric Company | Method of infiltration forming a silicon carbide body with improved surface finish |
DE4438456C2 (en) * | 1994-10-28 | 2002-07-11 | Deutsch Zentr Luft & Raumfahrt | Friction unit |
DE29610498U1 (en) | 1996-06-14 | 1996-08-29 | Zornik, Miklavz, Lesce | Vehicle brake or vehicle clutch disc made of C-C / SiC material |
-
1998
- 1998-07-28 DE DE19834018A patent/DE19834018C1/en not_active Expired - Fee Related
-
1999
- 1999-06-19 EP EP99111831A patent/EP0976698B1/en not_active Expired - Lifetime
- 1999-06-19 DE DE59907350T patent/DE59907350D1/en not_active Expired - Lifetime
- 1999-07-16 US US09/354,681 patent/US6358565B1/en not_active Expired - Lifetime
Cited By (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6627143B2 (en) * | 1999-02-09 | 2003-09-30 | Ngk Insulators, Ltd. | SiC—C/C composite material, uses thereof, and method for producing the same |
US20020084558A1 (en) * | 1999-02-09 | 2002-07-04 | Ngk Insulators, Ltd. | SiC-C/C composite material, uses thereof, and method for producing the same |
US6818085B2 (en) | 2000-03-24 | 2004-11-16 | Daimlerchrysler Ag | Fiber-reinforced structural component |
US20020179225A1 (en) * | 2000-03-24 | 2002-12-05 | Thomas Behr | Fiber-reinforced structural component |
US7037602B2 (en) | 2002-07-04 | 2006-05-02 | Sgl Carbon Ag | Multilayer composite |
US20060062984A1 (en) * | 2002-07-04 | 2006-03-23 | Bodo Benitsch | Multilayer composite |
EP1380809A2 (en) * | 2002-07-10 | 2004-01-14 | Sgl Carbon Ag | Ceramic composite bodies |
US20040197542A1 (en) * | 2002-07-10 | 2004-10-07 | Bodo Benitsch | Ceramic composite body, method for fabricating ceramic composite bodies, and armor using ceramic composite bodies |
EP1380809A3 (en) * | 2002-07-10 | 2004-05-26 | Sgl Carbon Ag | Ceramic composite bodies |
US7128963B2 (en) | 2002-07-10 | 2006-10-31 | Sgl Carbon Ag | Ceramic composite body, method for fabricating ceramic composite bodies, and armor using ceramic composite bodies |
US20140323636A1 (en) * | 2011-12-13 | 2014-10-30 | Lg Hausys, Ltd. | Synthetic marble with high hardness and method of manufacturing the same |
GB2582379A (en) * | 2019-03-22 | 2020-09-23 | Tenmat Ltd | Method of coating carbon components |
GB2582379B (en) * | 2019-03-22 | 2021-12-08 | Tenmat Ltd | Method of coating carbon components |
RU2822187C1 (en) * | 2023-12-19 | 2024-07-03 | Акционерное общество "Уральский научно-исследовательский институт композиционных материалов" | Methods of making sealed articles from composite materials (versions) and housing of high-temperature chemical reactor made by these methods |
Also Published As
Publication number | Publication date |
---|---|
DE59907350D1 (en) | 2003-11-20 |
EP0976698A1 (en) | 2000-02-02 |
DE19834018C1 (en) | 2000-02-03 |
EP0976698B1 (en) | 2003-10-15 |
US6358565B1 (en) | 2002-03-19 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US6358565B1 (en) | Method for making a protective coating containing silicon carbide | |
US4944904A (en) | Method of obtaining a fiber-containing composite | |
US5015540A (en) | Fiber-containing composite | |
EP0518589B1 (en) | Silicon carbide composite with metal boride coated fiber reinforcement | |
EP0519644B1 (en) | Silicon carbide composite with metal nitride coated fiber reinforcement | |
US5552352A (en) | Silicon carbide composite with coated fiber reinforcement | |
US5021367A (en) | Fiber-containing composite | |
JP4960082B2 (en) | Method for siliciding heat-resistant structural composite materials and components obtained by the method | |
US4889686A (en) | Composite containing coated fibrous material | |
US4981822A (en) | Composite containing coated fibrous material | |
EP1028098A2 (en) | SiC-C/C composite material, uses thereof and method for producing the same | |
US20030057040A1 (en) | Brake system having a composite-material brake disc | |
US5571758A (en) | Nitrogen-reacted silicon carbide material | |
JP2007513854A5 (en) | ||
EP1028099A1 (en) | Fibrous composite material and process for producing the same | |
US20060269683A1 (en) | Silicon carbide-based, porous, lightweight, heat-resistant structural material and manufacturing method therefor | |
US20080220256A1 (en) | Methods of coating carbon/carbon composite structures | |
EP1284251A1 (en) | Silicon carbide-based, porous, lightweight, heat-resistant structural material and manufacturing method therefor | |
EP2111382B1 (en) | Improvements in or relating to brake and clutch discs | |
EP0519643B1 (en) | Silicon carbide composite with metal carbide coated fiber reinforcement | |
EP1136463A2 (en) | Oxidation resistant carbonaceous material and method for producing the same | |
WO2008093078A1 (en) | Improvements in or relating to brake and clutch discs | |
GB2250516A (en) | Fiber-containing composite | |
US20040258919A1 (en) | Oxidation protective coating method for carbon/carbon composites | |
CA1321869C (en) | Fiber-containing composite |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: DEUTSCHES ZENTRUM FUER LUFT-UN RAUMFAHRT E.V., GER Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:KRENKEL, WALTER;HENKE, THILO;REEL/FRAME:010111/0989 Effective date: 19990702 |
|
STCF | Information on status: patent grant |
Free format text: PATENTED CASE |
|
FPAY | Fee payment |
Year of fee payment: 4 |
|
REMI | Maintenance fee reminder mailed | ||
FEPP | Fee payment procedure |
Free format text: PAT HOLDER NO LONGER CLAIMS SMALL ENTITY STATUS, ENTITY STATUS SET TO UNDISCOUNTED (ORIGINAL EVENT CODE: STOL); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY |
|
FPAY | Fee payment |
Year of fee payment: 8 |
|
FPAY | Fee payment |
Year of fee payment: 12 |