CA1240711A - Sintered polycrystalline composite materials based on boron nitride - Google Patents
Sintered polycrystalline composite materials based on boron nitrideInfo
- Publication number
- CA1240711A CA1240711A CA000504410A CA504410A CA1240711A CA 1240711 A CA1240711 A CA 1240711A CA 000504410 A CA000504410 A CA 000504410A CA 504410 A CA504410 A CA 504410A CA 1240711 A CA1240711 A CA 1240711A
- Authority
- CA
- Canada
- Prior art keywords
- boron nitride
- oxide
- weight
- breakring
- composite material
- 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.)
- Expired
Links
Classifications
-
- 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
- C04B35/58—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 borides, nitrides, i.e. nitrides, oxynitrides, carbonitrides or oxycarbonitrides or silicides
- C04B35/583—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 borides, nitrides, i.e. nitrides, oxynitrides, carbonitrides or oxycarbonitrides or silicides based on boron nitride
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
- B22D11/04—Continuous casting of metals, i.e. casting in indefinite lengths into open-ended moulds
- B22D11/045—Continuous casting of metals, i.e. casting in indefinite lengths into open-ended moulds for horizontal casting
- B22D11/047—Means for joining tundish to mould
- B22D11/0475—Means for joining tundish to mould characterised by use of a break ring
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- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Ceramic Engineering (AREA)
- Mechanical Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Structural Engineering (AREA)
- Organic Chemistry (AREA)
- Ceramic Products (AREA)
- Continuous Casting (AREA)
- Compositions Of Oxide Ceramics (AREA)
Abstract
ABSTRACT OF THE INVENTION
The invention is sintered polycrystalline composite materials based on boron nitride useful as brearings in the horizontal continuous casting of steel. These composite materials are produced by hot-pressing powder mixtures of hexagonal boron nitride and from 1 to 70% by weight of oxide(s), based on the total weight of the mixture, selected from the group consisting of zirconium oxide, magnesium oxide, aluminium oxide and silicon oxide, at temperatures in the range of from 1600 to 2000°C under a pressure of from 7 to 20 MPa. The preferred starting materials are boron nitride powders having an oxygen content of from 6 to 10% by weight and a specific surface area of from 5 to 30 m2/g (measured according to the BET method) and oxide powders, individually or in admixture, each having a purity > 97%.
The invention is sintered polycrystalline composite materials based on boron nitride useful as brearings in the horizontal continuous casting of steel. These composite materials are produced by hot-pressing powder mixtures of hexagonal boron nitride and from 1 to 70% by weight of oxide(s), based on the total weight of the mixture, selected from the group consisting of zirconium oxide, magnesium oxide, aluminium oxide and silicon oxide, at temperatures in the range of from 1600 to 2000°C under a pressure of from 7 to 20 MPa. The preferred starting materials are boron nitride powders having an oxygen content of from 6 to 10% by weight and a specific surface area of from 5 to 30 m2/g (measured according to the BET method) and oxide powders, individually or in admixture, each having a purity > 97%.
Description
7~
SI2JTE~D POI,YC~.YST~LLI~ cor~posITE MATl~RIALS BASED
OM BORON MITP~ID~
The invention relates to sintered polycrystalline composite materials based on boron nitrid2 for use as breakrings in the horizontal continuous casting of steel.
BA5KGROUr~D !:)F TF~E INVENTIOll:
In the field of the continuous casting of steel, in addition to the vertical and billet casting plants, horizontal casting plants have also been developed. The advan'ages of horizontal continuous casting as compared with conventional continuous casting are the ]ow overall height and construction costs of the plant, protection of toe melt from re-oxidation and freedom Erom deformation of the billet. horizontal continuous casting plants are especially suitable for the casting of relatively small melts, high-alloy special stee]s and simple constructional steels used in quantities.
In the horizontal continuous casting of steel, the casting mold is connected in an air-tight manner to a distributor vessel.
The solidification of the steel, that is the formation of the billet shell in the casting mould, occurs not as in the case of all other contlnuous casting plants at a phase interface between liquid steel and the surrounding gas, but in a continuous liquid phase. This requires special means to ensure that solidification occurs at a specific point in the casting mold.
The function of the distributor is to ensure a constant flow of molten metal and to distribute the molten metal evenly among the billets. The transition to the casting mold is formed of furnace brick which is firmly set into the furnace and on the side towards the casting mo]d comprises a discharge nozzle which 1 .
7~
is generally formed from a high-grade refractory material such as, for example, zirconium oxide, since it has to absorb high thermal stresses. Adjacent the discharge nozzle is the break ring whicb is a component that is characteristic of the horizontal continuous casting process. The breakring has to ensure, in continuous operation, that prom that point onwards the billet shel1 begins to form. It thus serves precisely to determine the site of soli-dification of the billet in relation to the casting mold. Since it is unavoidable that a shell will also form on the break ring, the shell must be easily removable and must not form any interphase with the material of the break ring. In aadition, high resistance to thermal shock and high abrasion resistance are required. The lack of a suitable material which satisfies these requirements -for the break ring is one of the main reasons why horizontal continuous casting of steel has not hitherto won recognition in practical operation, although the process per se has been known for more than 100 years.
In plants for horizontal continuous casting of steel that have been developed since 19~0, breakrings of ceramic material, such as .silicon nitride, zirconium oxide, boron nitride or aluminium nitride, have been used to solve the problem of providing an operationally reliable transition prom the holding furnace to the casting mold. It also became known, however, that when, for example, silicon nitride brearings were used, typical defects of horizontal continuous casting, such as transverse cracks on the surface upon drawing the solidified billet out of the casting mould, could not be prevented. on improvement in the durability of the ceramic connection between the holding vessel and casting mold is therefore considered to be imperative (cf. R.
Thielmann and I. Steffen in "Stahl und Eisen" 100 (1~80), Jo. 7, pages ~0l-407).
~137~
Refractory composite materials based on oxides r"hich, because ox the addition of graphite, are especially durable and have therefore proved useful for immersion nozzles in conventional continuous casting processes (cf. ~E-A-29 36 480 and DE 30 03 045 C 2) cannot, however, be used for breakrings in horizontal contirluous casting. Breakrings containing graphite cannot be used for horizontal continuous casting of high-alloy special steels which are especially susceptible to the absorption of carbon.
Refractory materials consisting of sintered stabilized zirconium oxide with a boron nitride content of not more than 20%
(cf. Jpn. Rokai Tokkyo Koho JP 59 21, 575, reE. in C.A. 100:
1967~e (198~)) are no more suitable for breakrings than those base solely on oxides or nitrides since chipping and erosion of the breakring cannot be avoided. This results not only in increased wear of the breakrings themselves but also in the embedd;rlg ox undesirable material in the steel which, in the case of the long casting times required for high-alloy special steels, leads to a marked diminution ln quality.
aterials based solely on boron nitride have the advantager as compared with the other known materials, that they are virtua]ly unwetted by steel and steel alloys and, in addition, are easily worked. It is important that the material for the break-ring can he easily worked since an accurate fit of the breakring is requirea between the discharge nozzle and the mold.
The problem is, to improve the material based on boron nitride by selecting suitable additives so that the composite satisfies the requirements for use as a breakring in the hori-zontal contirluous casting of steel.
BRIEF ~ESCRIPTIO~ OF TOE INVENTION
_ _ . ... .
According to the invention, this problem is solved by _~_ 7~
forming breakrings from sintered polycrystalline composite materials based on boron nitride that have been manuactured by hot~pressing powder mixtures of hexagonal boron nitride and from 1 to 70~ by weight of at least one oxide based on the total weight of the mixture, selected from the group consisting of zirconium oxide, magneslum oxide, aluminium oxide and silicon oxide, at temperatures in the range of from 1,600 to 2,000C under pressure of from 7 to 20 ~.~PaO
The starting materials employed for the manufacture of the composite materials used in accordance with the invention are preferably hexagonal boron nitride powders having an oxygen content of from 5 to 10% by weight and a specific surface area of from 5 to 30 m /g (measured according to the ~r5T method) and the oxide powders, individually or in admixture, each having 3 purity of at least 7 97~.
The powders are homogeneollsly mixed ina manner known per se in a conventional. mixing apparatus, optionally with the use of a temporary binder, and then hot-pressed in graphite molds under biaxial app7ication of pressure at temperatures of pre.erably from about l700 to 1~00C under a pressure of preferably from about 9 to ll Pa The breakrirlgs are cut from the resulting blocks in the desired dimensions and worked into their final shape.
The composite materials useful i.n the practice of the invention are predominarltly of a hexagonal boron nitride phase, and the oxide phases, the boron nitride phase being bonded to the boron oxide present in the starting powder (expressed by the oxygen content in the given range, which acts as a sintering aid he].ieved to be partly formed from boroxinitride phases.
Composite materials in which the hexagonal boron nitride portion is from ~0 to 60~ by weight and the oxide portion consists of zirconium oxide or magnesium oxide, and which have a density of at least 94% of the theoretically possible density (based on the boron nitride and oxide mixture), have proved especially useful as breakrings for contirluous horizontal casting processes.
In comparison with breakrings formed from a sintered polycrystalline materal consistirlg solely ox boron nitride, the composite materials used according to the invention exhibited considerably improved wear behavior when used as breakrings in the horizontal continuous casting of various types of steel. The subject matter of the invention is described in detail in the fol]owing examples.
~xam~le l a) A powder mixture of 30% by weight zirconium oxide (purity: 98~), 68% by weight boron nitride t2 content 7~ by weight, speci-fic surface area 10 m2/g) and 2% by weight of a temporary binder was hot-pressed in graphite molds at 1800C and lD Pupa to form a sintered body. The block size was d 200 and length 200 mm. The density obtained was 9~% of the theoretical density (TD).
b) Under the same conditions, a powder mixture of 98% by weight of the boron nitride powder and 2% by weight of the temporary binder was hot-pressed. density obtained: 94~ To.
Rings having the dimensions do 65 x di ~5 x 12.7 mm and do 165 x di 120 x 12.7 mm and samples for further tests were worked from these bodies. Table 1 shows the results obtained in compari-son with boron nitride. The ring (do 1~5 x di 120 x 12.7 mm) was used to cast stainless steel. With this quality of steel, erosion at the exit side of the breakring occurred to an increased extent when pure boron nitride breakrings were used. Table 2 aives the results obtained in comparison.
~0~1~
The ring do 65 x di 45 x 12.7 mm was used to cast high cobalt-alloy steel. In this case also, the usual erosion at the exit side of the pure boron nitride breakring occurred. Table 2 shows the results obtained.
In the examples, do refers to outside diameter and di, refers to inside diameter of the breakring.
Example 2:
powder mixture of 30~ by weight magnesium oxide (purity:
98~), 68 % by weight boron nit,irde from example la) and 2% by weight oE a temporary binder was hot-pressed at 1700r and 10 MPa to form a sintered body. The block size was d 180 and length 200 mm. The density obtained was 94~ of the theoretical density.
Breakrings having the dimension do 165 x di 120 x 12.7 mm were likewise worked from this body. Table 1 shows the measured va]ues obtained in comparison with boron nitride. stainless steel was cast using the breakring. Table 2 shows the results obtained in comparison with boron nitride.
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SI2JTE~D POI,YC~.YST~LLI~ cor~posITE MATl~RIALS BASED
OM BORON MITP~ID~
The invention relates to sintered polycrystalline composite materials based on boron nitrid2 for use as breakrings in the horizontal continuous casting of steel.
BA5KGROUr~D !:)F TF~E INVENTIOll:
In the field of the continuous casting of steel, in addition to the vertical and billet casting plants, horizontal casting plants have also been developed. The advan'ages of horizontal continuous casting as compared with conventional continuous casting are the ]ow overall height and construction costs of the plant, protection of toe melt from re-oxidation and freedom Erom deformation of the billet. horizontal continuous casting plants are especially suitable for the casting of relatively small melts, high-alloy special stee]s and simple constructional steels used in quantities.
In the horizontal continuous casting of steel, the casting mold is connected in an air-tight manner to a distributor vessel.
The solidification of the steel, that is the formation of the billet shell in the casting mould, occurs not as in the case of all other contlnuous casting plants at a phase interface between liquid steel and the surrounding gas, but in a continuous liquid phase. This requires special means to ensure that solidification occurs at a specific point in the casting mold.
The function of the distributor is to ensure a constant flow of molten metal and to distribute the molten metal evenly among the billets. The transition to the casting mold is formed of furnace brick which is firmly set into the furnace and on the side towards the casting mo]d comprises a discharge nozzle which 1 .
7~
is generally formed from a high-grade refractory material such as, for example, zirconium oxide, since it has to absorb high thermal stresses. Adjacent the discharge nozzle is the break ring whicb is a component that is characteristic of the horizontal continuous casting process. The breakring has to ensure, in continuous operation, that prom that point onwards the billet shel1 begins to form. It thus serves precisely to determine the site of soli-dification of the billet in relation to the casting mold. Since it is unavoidable that a shell will also form on the break ring, the shell must be easily removable and must not form any interphase with the material of the break ring. In aadition, high resistance to thermal shock and high abrasion resistance are required. The lack of a suitable material which satisfies these requirements -for the break ring is one of the main reasons why horizontal continuous casting of steel has not hitherto won recognition in practical operation, although the process per se has been known for more than 100 years.
In plants for horizontal continuous casting of steel that have been developed since 19~0, breakrings of ceramic material, such as .silicon nitride, zirconium oxide, boron nitride or aluminium nitride, have been used to solve the problem of providing an operationally reliable transition prom the holding furnace to the casting mold. It also became known, however, that when, for example, silicon nitride brearings were used, typical defects of horizontal continuous casting, such as transverse cracks on the surface upon drawing the solidified billet out of the casting mould, could not be prevented. on improvement in the durability of the ceramic connection between the holding vessel and casting mold is therefore considered to be imperative (cf. R.
Thielmann and I. Steffen in "Stahl und Eisen" 100 (1~80), Jo. 7, pages ~0l-407).
~137~
Refractory composite materials based on oxides r"hich, because ox the addition of graphite, are especially durable and have therefore proved useful for immersion nozzles in conventional continuous casting processes (cf. ~E-A-29 36 480 and DE 30 03 045 C 2) cannot, however, be used for breakrings in horizontal contirluous casting. Breakrings containing graphite cannot be used for horizontal continuous casting of high-alloy special steels which are especially susceptible to the absorption of carbon.
Refractory materials consisting of sintered stabilized zirconium oxide with a boron nitride content of not more than 20%
(cf. Jpn. Rokai Tokkyo Koho JP 59 21, 575, reE. in C.A. 100:
1967~e (198~)) are no more suitable for breakrings than those base solely on oxides or nitrides since chipping and erosion of the breakring cannot be avoided. This results not only in increased wear of the breakrings themselves but also in the embedd;rlg ox undesirable material in the steel which, in the case of the long casting times required for high-alloy special steels, leads to a marked diminution ln quality.
aterials based solely on boron nitride have the advantager as compared with the other known materials, that they are virtua]ly unwetted by steel and steel alloys and, in addition, are easily worked. It is important that the material for the break-ring can he easily worked since an accurate fit of the breakring is requirea between the discharge nozzle and the mold.
The problem is, to improve the material based on boron nitride by selecting suitable additives so that the composite satisfies the requirements for use as a breakring in the hori-zontal contirluous casting of steel.
BRIEF ~ESCRIPTIO~ OF TOE INVENTION
_ _ . ... .
According to the invention, this problem is solved by _~_ 7~
forming breakrings from sintered polycrystalline composite materials based on boron nitride that have been manuactured by hot~pressing powder mixtures of hexagonal boron nitride and from 1 to 70~ by weight of at least one oxide based on the total weight of the mixture, selected from the group consisting of zirconium oxide, magneslum oxide, aluminium oxide and silicon oxide, at temperatures in the range of from 1,600 to 2,000C under pressure of from 7 to 20 ~.~PaO
The starting materials employed for the manufacture of the composite materials used in accordance with the invention are preferably hexagonal boron nitride powders having an oxygen content of from 5 to 10% by weight and a specific surface area of from 5 to 30 m /g (measured according to the ~r5T method) and the oxide powders, individually or in admixture, each having 3 purity of at least 7 97~.
The powders are homogeneollsly mixed ina manner known per se in a conventional. mixing apparatus, optionally with the use of a temporary binder, and then hot-pressed in graphite molds under biaxial app7ication of pressure at temperatures of pre.erably from about l700 to 1~00C under a pressure of preferably from about 9 to ll Pa The breakrirlgs are cut from the resulting blocks in the desired dimensions and worked into their final shape.
The composite materials useful i.n the practice of the invention are predominarltly of a hexagonal boron nitride phase, and the oxide phases, the boron nitride phase being bonded to the boron oxide present in the starting powder (expressed by the oxygen content in the given range, which acts as a sintering aid he].ieved to be partly formed from boroxinitride phases.
Composite materials in which the hexagonal boron nitride portion is from ~0 to 60~ by weight and the oxide portion consists of zirconium oxide or magnesium oxide, and which have a density of at least 94% of the theoretically possible density (based on the boron nitride and oxide mixture), have proved especially useful as breakrings for contirluous horizontal casting processes.
In comparison with breakrings formed from a sintered polycrystalline materal consistirlg solely ox boron nitride, the composite materials used according to the invention exhibited considerably improved wear behavior when used as breakrings in the horizontal continuous casting of various types of steel. The subject matter of the invention is described in detail in the fol]owing examples.
~xam~le l a) A powder mixture of 30% by weight zirconium oxide (purity: 98~), 68% by weight boron nitride t2 content 7~ by weight, speci-fic surface area 10 m2/g) and 2% by weight of a temporary binder was hot-pressed in graphite molds at 1800C and lD Pupa to form a sintered body. The block size was d 200 and length 200 mm. The density obtained was 9~% of the theoretical density (TD).
b) Under the same conditions, a powder mixture of 98% by weight of the boron nitride powder and 2% by weight of the temporary binder was hot-pressed. density obtained: 94~ To.
Rings having the dimensions do 65 x di ~5 x 12.7 mm and do 165 x di 120 x 12.7 mm and samples for further tests were worked from these bodies. Table 1 shows the results obtained in compari-son with boron nitride. The ring (do 1~5 x di 120 x 12.7 mm) was used to cast stainless steel. With this quality of steel, erosion at the exit side of the breakring occurred to an increased extent when pure boron nitride breakrings were used. Table 2 aives the results obtained in comparison.
~0~1~
The ring do 65 x di 45 x 12.7 mm was used to cast high cobalt-alloy steel. In this case also, the usual erosion at the exit side of the pure boron nitride breakring occurred. Table 2 shows the results obtained.
In the examples, do refers to outside diameter and di, refers to inside diameter of the breakring.
Example 2:
powder mixture of 30~ by weight magnesium oxide (purity:
98~), 68 % by weight boron nit,irde from example la) and 2% by weight oE a temporary binder was hot-pressed at 1700r and 10 MPa to form a sintered body. The block size was d 180 and length 200 mm. The density obtained was 94~ of the theoretical density.
Breakrings having the dimension do 165 x di 120 x 12.7 mm were likewise worked from this body. Table 1 shows the measured va]ues obtained in comparison with boron nitride. stainless steel was cast using the breakring. Table 2 shows the results obtained in comparison with boron nitride.
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Claims (7)
1. A sintered polycrystalline composite materal based on boron nitride and useful for a breakring in the horizontal continuous casting of steel, and wherein said composite material is manufactured by a process comprising hot-pressing a powder mixture of from about 60 to 80% by weight of hexagonal boron nitride having an oxygen content from 6 to 10% by weight and a specific surface area of from 5 to 30 m2/g, and from 40 to 20% by weight based on the total weight of the mixture, of at least one oxide selected from the group consisting of zirconium oxide and magnesium oxide, at a temperature in the range of from about l600 to 2000°C. under a pressure of from about 7 to 20 MPa to provide said composite material having a density of at least 94% of the theoretical density.
2. The sintered polycrystalline-material of claim 1 which is essentially free of cubic boron nitride.
3. The sintered polycrystallline material of claim 1 which is essentially free of calcium oxide.
4. A breakring for use between the discharge nozzel, of a holding vessel and a casting mold in the horizontal continuous method for the casting of steel, said breakring comprised of a sintered polycrystalline composite material based on boron nitride wherein said composite material is manufactured by a process comprising: hot-pressing a powder mixture of from 60 to 80% by weight of hexagonal boron nitride having an oxygen content of from 6 to 10% by weight and a specific surface area of from 5 to 30 m2/g, and from 40 to 20% by weight based on the total weight of the mixture, of at least one oxide selected from the group consisting of zirconium oxide and magnesium oxide, the oxides individually or in admixture, each having a purity of 97%, at a temperature in the range of from about 1600 to 2000°C. under a pressure of from about 7 to 20 MPa.
5. The breakring of claim 4 wherein said composite material is essentially free of cubic boron nitride.
6. The breakring of claim 4 wherein said composite material is essentially free of calcium oxide.
7. The breakring of claim 4 having an outer diameter of from about 165 to about 65 mm, an inner diameter of from about 120 to about 45 mm and a thickness of about 12.7 mm.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP3510111.3 | 1985-03-20 | ||
| DE19853510111 DE3510111A1 (en) | 1985-03-20 | 1985-03-20 | Sintered polycrystalline blends based on boron nitride |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1240711A true CA1240711A (en) | 1988-08-16 |
Family
ID=6265830
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000504410A Expired CA1240711A (en) | 1985-03-20 | 1986-03-18 | Sintered polycrystalline composite materials based on boron nitride |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP0195417B1 (en) |
| JP (1) | JPS61215261A (en) |
| AT (1) | ATE41139T1 (en) |
| CA (1) | CA1240711A (en) |
| DE (2) | DE3510111A1 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5246896A (en) * | 1990-10-18 | 1993-09-21 | Foesco International Limited | Ceramic composition |
| EP1213273B2 (en) † | 2000-11-09 | 2009-10-07 | ESK Ceramics GmbH & Co.KG | Method of recycling side-dam plates for thin sheet casting of steel |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4904625A (en) * | 1986-10-03 | 1990-02-27 | Union Carbide Corporation | Refractory composites of alumina and boron nitride |
| DE3824849A1 (en) * | 1988-07-21 | 1990-01-25 | Kempten Elektroschmelz Gmbh | PRESSURIZED POLYCRYSTALLINE MIXING MATERIALS BASED ON HEXAGONAL BORNITRIDE, OXIDES AND CARBIDES |
| JPH0328171A (en) * | 1989-06-23 | 1991-02-06 | Nec Corp | Ceramic composition material |
| US5083687A (en) * | 1989-10-19 | 1992-01-28 | Kawasaki Steel Corporation | Nozzle for continuous casting and method of producing |
| GB9022638D0 (en) * | 1990-10-18 | 1990-11-28 | Unicorn Ind Plc | Ceramic composition |
| DE19714203C2 (en) * | 1997-04-07 | 2000-06-29 | Bosch Gmbh Robert | Sealing element for sensors |
| DE19848959A1 (en) * | 1998-10-23 | 2000-04-27 | Bosch Gmbh Robert | Production of boron nitride-ring for sensor for determining oxygen concentration in exhaust gas from combustion engine involves simultaneously forming several boron nitride rings in composite |
| DE10015849A1 (en) * | 2000-03-30 | 2001-10-18 | Kempten Elektroschmelz Gmbh | Ceramic material used in the production of sintered bodies contains boron nitride, an additive selected from oxides, carbides and nitrides of silicon, aluminum, titanium and zirconium |
| JP5728684B2 (en) * | 2011-02-04 | 2015-06-03 | 名古屋市 | Free-cutting ceramics and manufacturing method thereof |
| CN111807844A (en) * | 2020-06-01 | 2020-10-23 | 福州派尔盛陶瓷有限公司 | Preparation method of boron nitride composite material |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SU441255A1 (en) * | 1973-03-27 | 1974-08-30 | Ордена Трудового Красного Знамени Институт Проблем Материаловедения Академии Наук Украинской Сср | Ceramic material |
| JPS50729A (en) * | 1973-05-02 | 1975-01-07 | ||
| DE2629960C3 (en) * | 1976-07-02 | 1981-08-06 | Moskovskij chimiko-technologičeskij institut imeni D.I. Mendeleeva, Moskva | Process for the manufacture of products based on hexagonal boron nitride |
| JPS5919073B2 (en) * | 1976-10-04 | 1984-05-02 | 電気化学工業株式会社 | Method for manufacturing sintered compacts |
| US4304870A (en) * | 1980-02-20 | 1981-12-08 | The United States Of America As Represented By The Secretary Of The Navy | Ablative-resistant dielectric ceramic articles |
| JPS56139260A (en) * | 1980-03-31 | 1981-10-30 | Shinagawa Refract Co Ltd | Nozzle for casting |
| SE422322B (en) * | 1980-06-30 | 1982-03-01 | Asea Ab | Process for the preparation of an insulating material for thermo elements used in high-pressure furnaces |
| JPS5988375A (en) * | 1982-11-09 | 1984-05-22 | 住友電気工業株式会社 | Sintered body for high hard tool and manufacture |
| JPS59169982A (en) * | 1983-03-17 | 1984-09-26 | 黒崎窒業株式会社 | Boron nitride containing refractories |
-
1985
- 1985-03-20 DE DE19853510111 patent/DE3510111A1/en not_active Withdrawn
-
1986
- 1986-03-18 EP EP86103669A patent/EP0195417B1/en not_active Expired
- 1986-03-18 DE DE8686103669T patent/DE3662255D1/en not_active Expired
- 1986-03-18 CA CA000504410A patent/CA1240711A/en not_active Expired
- 1986-03-18 AT AT86103669T patent/ATE41139T1/en not_active IP Right Cessation
- 1986-03-20 JP JP61061004A patent/JPS61215261A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5246896A (en) * | 1990-10-18 | 1993-09-21 | Foesco International Limited | Ceramic composition |
| EP1213273B2 (en) † | 2000-11-09 | 2009-10-07 | ESK Ceramics GmbH & Co.KG | Method of recycling side-dam plates for thin sheet casting of steel |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS61215261A (en) | 1986-09-25 |
| EP0195417A1 (en) | 1986-09-24 |
| DE3662255D1 (en) | 1989-04-13 |
| DE3510111A1 (en) | 1986-09-25 |
| ATE41139T1 (en) | 1989-03-15 |
| EP0195417B1 (en) | 1989-03-08 |
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