KR20100008912A - Silicon carbide heater and manufacturing method thereof - Google Patents
Silicon carbide heater and manufacturing method thereof Download PDFInfo
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- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 title claims abstract description 80
- 229910010271 silicon carbide Inorganic materials 0.000 title claims abstract description 70
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 24
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims abstract description 80
- 238000010438 heat treatment Methods 0.000 claims abstract description 59
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims abstract description 55
- 229910052710 silicon Inorganic materials 0.000 claims abstract description 44
- 239000010703 silicon Substances 0.000 claims abstract description 44
- 229910052757 nitrogen Inorganic materials 0.000 claims abstract description 37
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 18
- 238000000465 moulding Methods 0.000 claims abstract description 16
- 239000000203 mixture Substances 0.000 claims abstract description 12
- 239000011863 silicon-based powder Substances 0.000 claims abstract description 11
- 238000002156 mixing Methods 0.000 claims abstract description 4
- 238000006243 chemical reaction Methods 0.000 claims description 41
- 238000000034 method Methods 0.000 claims description 31
- 238000005245 sintering Methods 0.000 claims description 11
- 239000000843 powder Substances 0.000 claims description 8
- 229910001873 dinitrogen Inorganic materials 0.000 claims description 6
- 239000010439 graphite Substances 0.000 claims description 5
- 229910002804 graphite Inorganic materials 0.000 claims description 5
- 229910052581 Si3N4 Inorganic materials 0.000 claims description 4
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 claims description 4
- 239000006229 carbon black Substances 0.000 claims description 3
- 229910052799 carbon Inorganic materials 0.000 claims description 2
- 238000007493 shaping process Methods 0.000 claims description 2
- 239000000463 material Substances 0.000 abstract description 10
- 238000005507 spraying Methods 0.000 abstract 1
- 230000008859 change Effects 0.000 description 16
- 239000007789 gas Substances 0.000 description 16
- 230000000052 comparative effect Effects 0.000 description 11
- 238000004458 analytical method Methods 0.000 description 10
- 230000008569 process Effects 0.000 description 10
- 238000005259 measurement Methods 0.000 description 7
- 238000002149 energy-dispersive X-ray emission spectroscopy Methods 0.000 description 5
- 239000002245 particle Substances 0.000 description 5
- 238000002441 X-ray diffraction Methods 0.000 description 3
- 230000008901 benefit Effects 0.000 description 3
- 239000002800 charge carrier Substances 0.000 description 3
- 239000007788 liquid Substances 0.000 description 3
- 238000013021 overheating Methods 0.000 description 3
- 230000005540 biological transmission Effects 0.000 description 2
- 238000003763 carbonization Methods 0.000 description 2
- 239000011362 coarse particle Substances 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000020169 heat generation Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 239000011148 porous material Substances 0.000 description 2
- 238000001953 recrystallisation Methods 0.000 description 2
- 239000004065 semiconductor Substances 0.000 description 2
- 230000009466 transformation Effects 0.000 description 2
- 239000011230 binding agent Substances 0.000 description 1
- 229910010293 ceramic material Inorganic materials 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000005485 electric heating Methods 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 229910052575 non-oxide ceramic Inorganic materials 0.000 description 1
- 239000011225 non-oxide ceramic Substances 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
- 230000006798 recombination Effects 0.000 description 1
- 238000005215 recombination Methods 0.000 description 1
- 239000011856 silicon-based particle Substances 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 239000007858 starting material Substances 0.000 description 1
- 238000004627 transmission electron microscopy Methods 0.000 description 1
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- 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
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- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B3/00—Ohmic-resistance heating
- H05B3/10—Heating elements characterised by the composition or nature of the materials or by the arrangement of the conductor
- H05B3/12—Heating elements characterised by the composition or nature of the materials or by the arrangement of the conductor characterised by the composition or nature of the conductive material
- H05B3/14—Heating elements characterised by the composition or nature of the materials or by the arrangement of the conductor characterised by the composition or nature of the conductive material the material being non-metallic
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Abstract
Description
본 발명은 실리콘을 제거하여 전기 저항을 낮출 수 있는 탄화 규소 발열체 및 그의 제조 방법에 관한 것이다.The present invention relates to a silicon carbide heating element capable of lowering electrical resistance by removing silicon and a method of manufacturing the same.
탄화규소는 비산화물 세라믹스 중에서 가장 널리 사용되는 재료로써, 우수한 경도, 높은 기계적 강도 및 고온 강도, 우수한 내산화성과 높은 열전도도 및 넓은 밴드갭 에너지(2.8 ~ 3.2eV)를 갖는 반도체 특성을 갖고 있으며, 특히, 세라믹 재료에서는 찾아보기 힘든 수준의 낮은 비저항 특허(0.05 ~ 0.5Ω㎝)을 갖고 있어 전기 발열체로 널리 이용되고 있다.Silicon carbide is the most widely used material among non-oxide ceramics, and has semiconductor characteristics with excellent hardness, high mechanical strength and high temperature strength, excellent oxidation resistance and high thermal conductivity, and wide band gap energy (2.8 to 3.2 eV). In particular, it has a low specific resistance patent (0.05 ~ 0.5Ω ㎝) of the level rarely found in ceramic materials and is widely used as an electric heating element.
그러나, 강한 공유결합 재료이기 때문에 일반적인 소결방법만으로는 소결시킬 수 없다.However, since it is a strong covalent bond material, it cannot be sintered only by the general sintering method.
일반적으로 탄화규소는 2000℃ 부근의 매우 높은 온도에서 마이크로 미터 이하 크기의 입자를 출발 물질로 사용하거나 또는 매우 큰 압력으로 프레스하여 입자 의 표면 에너지를 활성화시켜 소결시킨다.In general, silicon carbide is sintered at very high temperatures around 2000 ° C. using particles of sub-micrometer size as starting material or by pressing at very high pressures to activate the surface energy of the particles.
그러나, 이와 같은 방법은 대량 생산 장비를 갖추기 어려우며, 제작 비용이 많이 소요되는 공정이기 때문에 상용 제품에 적용하는 데는 한계가 있다.However, such a method is difficult to equip the mass production equipment and is a process that requires a lot of manufacturing costs, there is a limit to apply to commercial products.
따라서, 반응 소결이라는 방법을 일반적으로 사용한다.Therefore, a method called reaction sintering is generally used.
여기서, 반응소결이란 탄화규소와 탄소 분말을 유기 결합재를 이용하여 성형한 후에, 고온 및 진공하에서 액상 실리콘을 성형체 내부에 존재하는 기공을 통하여 모세관 힘으로 침윤시키면, 탄화규소 분말 사이로 침윤된 액상 실리콘과 탄소 분말이 자발 반응하여 새로운 탄화규소가 생성되어 소결되는 방법이다.Here, the reaction sintering refers to the liquid silicon infiltrated between the silicon carbide powder when the silicon carbide and the carbon powder is molded using the organic binder, and then the liquid silicon is infiltrated by capillary force through the pores present inside the molded body under high temperature and vacuum. Carbon powder spontaneously reacts to produce new silicon carbide and sinter it.
액상실리콘이 나타나는 1410℃ 이상이면, 탄화규소 성형체는 손쉽게 소결될 수 있어 상업적으로 널리 사용되고 있으며, 공업용 로(Furnace)에 이용되는 탄화규소 발열체도 이와 같은 방법으로 제작되는 것으로 알려져 있다.If the liquid silicon is 1410 ℃ or more, the silicon carbide molded body can be easily sintered and widely used commercially, silicon carbide heating element used in industrial furnaces (Furnace) is also known to be produced in this way.
그러나, 이와 같은 방법으로 제작된 반응소결 탄화규소 소결체 내부에는 필연적으로 상당량의 미반응 실리콘이 남아 있게 되어 전기 저항이 낮아짐으로, 전기 저항에 의한 발열체로 사용하기 위해서는 전류 증폭기를 추가적으로 설치해야 되는 단점을 지니게 된다.However, since a large amount of unreacted silicon remains inevitably inside the reaction sintered silicon carbide sintered body manufactured in this way, the electrical resistance is lowered. Therefore, it is necessary to additionally install a current amplifier in order to use it as a heating element by the electrical resistance. Will be carried.
따라서, 반응 소결법으로 탄화규소 발열체를 제작하지 않고 재결정화 방법을 사용하여 잔류 실리콘 문제를 해결하기도 한다.Therefore, the problem of residual silicon may be solved by using a recrystallization method without producing a silicon carbide heating element by the reaction sintering method.
재결정화 방법이란, 매우 미세한 탄화규소 입자와 조대한 입자를 혼합하여 성형체를 제작한 후, 이를 2000℃ 부근으로 가열시킴으로써, 입자의 표면 에너지 차이에 의해 미세한 탄화규소 입자가 휘발되어 주위의 조대한 탄화규소 입자에 증 착되게 하여 소결을 도모하는 방법이다.In the recrystallization method, a very fine silicon carbide particle and coarse particles are mixed to form a molded body, and then heated to around 2000 ° C., whereby fine silicon carbide particles are volatilized due to the difference in surface energy of the particles, causing coarse carbonization to occur. It is a method of sintering by making it deposit on a silicon particle.
일반적으로 반도체 비저항의 온도 의존성은, 온도가 증가함에 따라 감소하는 NTC(Negative Temperature Coefficient) 현상을 보이다가, 다시 증가하는 PTC(Positive Temperature Coefficient) 현상을 보이는 것으로 알려져 있으며, 온도 변화에 따른 비저항 변화가 작을수록 저항 발열체로 사용했을 경우, 온도 제어가 더 용이하다.In general, the temperature dependence of the semiconductor resistivity is known to show a negative temperature coefficient (NTC) that decreases with increasing temperature, and then a positive temperature coefficient (PTC) that increases again. The smaller the value, the easier the temperature control is when used as a resistive heating element.
본 발명은 탄화규소 발열체 제조 후, 미반응 실리콘이 남아 있게 되어 전기 저항이 낮아지는 문제를 해결하는 것이다.The present invention is to solve the problem that the unresponsive silicon remains after the silicon carbide heating element is manufactured, the electrical resistance is lowered.
본 발명의 바람직한 양태(樣態)는, According to a preferred aspect of the present invention,
탄화규소 분말과 탄소 분말을 혼합하여 혼합물을 형성하는 단계와;Mixing the silicon carbide powder and the carbon powder to form a mixture;
상기 혼합물을 성형하여 성형물을 형성하는 단계와;Shaping the mixture to form a molding;
상기 성형물에 실리콘 분말을 뿌리고, 상기 성형물을 반응 소결시켜 상기 실리콘이 침윤된 반응 소결물을 형성하는 단계와;Sprinkling silicon powder on the molding, and reacting and sintering the molding to form a reaction sinter in which the silicon is infiltrated;
상기 반응 소결물에 잔류되어 있는 실리콘을 휘발시켜 제거하는 단계와;Volatilizing and removing the silicon remaining in the reaction sinter;
상기 반응 소결물에 질소를 도핑하는 단계로 구성된 탄화 규소 발열체를 제 조하는 방법이 제공된다.Provided is a method of manufacturing a silicon carbide heating element consisting of doping nitrogen into the reaction sinter.
본 발명은 실리콘 분말이 뿌려진 성형물을 반응 소결한 후, 잔류하는 실리콘을 휘발시키고, 질소를 도핑하여 휘발되지 못한 실리콘과 반응시켜, 발열체에서 실리콘을 완전히 제거함으로써, 발열체 용도에 적합한 수준으로 전기 저항을 낮출 수 있는 효과가 있다.The present invention reacts and sinters a molding sprayed with silicon powder, and then volatilizes the remaining silicon, reacts with silicon which is not volatilized by nitrogen, and completely removes silicon from the heating element, thereby reducing electrical resistance to a level suitable for heating element use. It can be lowered.
또한, 본 발명의 탄화 규소 발열체는 탄화규소 격자 내에 질소가 도핑되어 있으므로, 유동 전하 운반자가 존재하여 낮은 온도에서 빠른 온도 증가 특성을 갖고, 고온으로 갈수록 저항이 증가되어 자체적으로 과열되는 것을 억제할 수 있는 효과가 있다.In addition, since the silicon carbide heating element of the present invention is doped with nitrogen in the silicon carbide lattice, the presence of a flow charge carrier has a rapid temperature increase characteristic at low temperature, and the resistance increases as the temperature increases to suppress the overheating itself. It has an effect.
더불어, 본 발명에 따른 탄화 규소 발열체로 제작된 가스 점화기는 탄화 규소 발열체에 질소가 도핑되어 있으므로, 발열 속도를 향상시킬 수 있는 효과가 있다.In addition, since the gas igniter manufactured by the silicon carbide heating element according to the present invention is doped with nitrogen in the silicon carbide heating element, there is an effect of improving the heat generation rate.
이하, 첨부된 도면을 참조하여 본 발명의 바람직한 실시예를 설명하면 다음과 같다.Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.
도 1은 본 발명의 제 1 실시예에 따라 탄화 규소 발열체의 제조 방법을 설명하기 위한 개략적인 흐름도로서, 탄화규소 분말과 탄소 분말을 혼합하여 혼합물을 형성한다.(S110단계)FIG. 1 is a schematic flowchart illustrating a method of manufacturing a silicon carbide heating element according to a first embodiment of the present invention, in which silicon carbide powder and carbon powder are mixed to form a mixture.
상기 탄화규소 분말은 1-100㎛ 직경을 갖는 분말인 것이 바람직하다.The silicon carbide powder is preferably a powder having a diameter of 1-100㎛.
그리고, 상기 탄소 분말은 카본 블랙 분말 또는 흑연(Graphite) 분말을 사용하는 것이 바람직하다.In addition, the carbon powder is preferably carbon black powder or graphite (Graphite) powder.
이 혼합물은 탄화규소 분말과 탄소 분말을 용매에 넣고, 혼합하여 분산시킨 것이다.This mixture is made by dispersing silicon carbide powder and carbon powder in a solvent, mixing them.
그 후, 상기 혼합물을 성형하여 성형물을 형성한다.(S120단계)Thereafter, the mixture is molded to form a molded product.
상기 성형물은 성형틀에 넣어 성형하여 형성하는 것이다.The molded article is formed by molding into a molding die.
이어서, 상기 성형물에 실리콘 분말을 뿌리고, 상기 성형물을 반응 소결시켜 상기 실리콘이 침윤된 반응 소결물(燒結物)을 형성한다.(S130단계)Subsequently, the powder is sprayed with silicon powder, and the molded product is reacted and sintered to form a reaction sintered product in which the silicon is infiltrated.
여기서, 상기 실리콘 분말은 상기 성형물에 골고루 뿌린다.Here, the silicon powder is evenly sprayed on the molding.
그리고, 상기 실리콘 분말이 뿌려진 성형물을 진공로에서 1400 ~ 1600℃ 온도로 가열하면, 상기 실리콘 분말은 용융되면서 상기 성형물의 기공을 통해 침윤된다.In addition, when the molded product sprayed with the silicon powder is heated in a vacuum furnace at a temperature of 1400 to 1600 ° C., the silicon powder is melted and infiltrated through the pores of the molded product.
침윤된 실리콘은 성형물 내의 탄소원인 카본 블랙 또는 흑연과 반응하여 새로운 탄화규소가 생성되면서 소결이 완성된다.The impregnated silicon reacts with carbon black or graphite, the carbon source in the molding, to produce new silicon carbide, which completes the sintering.
계속, 상기 반응 소결물에 잔류되어 있는 실리콘을 휘발시켜 제거한다.(S140단계)Subsequently, the silicon remaining in the reaction sinter is volatilized and removed.
상기 실리콘을 휘발시키는 것은 진공로에서 진공을 유지하면서 1400 ~ 1800℃의 온도에서 소정시간 동안 상기 반응 소결물을 열처리하면 된다.The volatilization of the silicon may be performed by heat treating the reaction sintered material at a temperature of 1400 to 1800 ° C. for a predetermined time while maintaining a vacuum in a vacuum furnace.
이렇게, 반응 소결물을 열처리하면 반응 소결 공정에서 미반응된 실리콘이 상당량 제거할 수 있게 된다.In this way, when the reaction sintered material is heat-treated, it is possible to remove a considerable amount of unreacted silicon in the reaction sintering process.
그러므로, 본 발명의 제 1 실시예에 따라 탄화 규소 발열체의 제조 방법은 반응 소결 후, 잔류하는 실리콘을 휘발시켜 제거할 수 있는 장점이 있는 것이다.Therefore, the method of manufacturing the silicon carbide heating element according to the first embodiment of the present invention has the advantage of volatilizing and removing the remaining silicon after the reaction sintering.
도 2는 본 발명의 제 2 실시예에 따라 탄화 규소 발열체의 제조 방법을 설명하기 위한 개략적인 흐름도로서, 탄화규소 분말과 탄소 분말을 혼합하여 혼합물을 형성한다.(S210단계)2 is a schematic flowchart illustrating a method for manufacturing a silicon carbide heating element according to a second embodiment of the present invention, in which silicon carbide powder and carbon powder are mixed to form a mixture (step S210).
그 후, 상기 혼합물을 성형하여 성형물을 형성한다.(S220단계)Thereafter, the mixture is molded to form a molded product.
이어서, 상기 성형물에 실리콘 분말을 뿌리고, 상기 성형물을 반응 소결시켜 상기 실리콘이 침윤된 반응 소결물을 형성한다.(S230단계)Subsequently, the powder is sprinkled with silicon powder and the molded product is reacted and sintered to form a reaction sintered product in which the silicon is infiltrated.
계속, 상기 반응 소결물에 잔류되어 있는 실리콘을 휘발시켜 제거한다.(S240단계)Subsequently, the silicon remaining in the reaction sinter is volatilized and removed.
상기 S210단계 내지 S240단계는 도 1의 공정과 동일하다.Steps S210 to S240 are the same as those of FIG. 1.
연이어, 상기 반응 소결물에 질소를 도핑한다.(S250단계)Subsequently, the reaction sintered material is doped with nitrogen.
여기서, 상기 반응 소결물에 질소를 도핑하면, 질소는 탄화규소 격자 내로 도핑된 후, 반응 소결물에 잔류되어 있는 나머지 실리콘이 질소와 반응되어 질화규소가 생성된다.Here, when nitrogen is doped into the reaction sinter, nitrogen is doped into the silicon carbide lattice, and the remaining silicon remaining in the reaction sinter is reacted with nitrogen to generate silicon nitride.
즉, S240단계에서 휘발되지 못한 나머지 실리콘이 도핑된 질소와 반응되어, Si + N → Si3N4와 같이 질화규소(Si3N4)가 생성되면서, 실리콘의 제거를 유도하게 된다.That is, the remaining silicon that is not volatilized in step S240 is reacted with the doped nitrogen, and silicon nitride (Si 3 N 4 ) is generated, such as Si + N → Si 3 N 4 , leading to the removal of silicon.
이러한, 질소 도핑 공정은 1400 ~ 1800℃의 온도에서 진공 분위기 대신에 질소 가스를 소정 압력으로 반응로에 공급하여 수행하는 것이 바람직하다.The nitrogen doping process is preferably performed by supplying nitrogen gas to the reactor at a predetermined pressure instead of a vacuum atmosphere at a temperature of 1400 to 1800 ° C.
즉, 휘발처리된 반응 소결물이 있는 반응로에 소정 압력으로 질소 가스를 공급하여 수행하는 것이다.That is, it is carried out by supplying nitrogen gas at a predetermined pressure to the reactor with the volatilized reaction sinter.
이때, 상기 질소 가스의 압력은 1기압 이상인 것이 바람직하다.At this time, the pressure of the nitrogen gas is preferably 1 atm or more.
보다 바람직하게는 1기압 ~ 100기압인 것이 좋다.More preferably, it is 1 atmosphere-100 atmospheres.
상기 질소 가스의 압력이 1기압 미만인 경우는 베타(Beta) SiC 상변태를 형성하기 어렵고, 100기압 이상에서는 반응 소결물에 원활하게 질소 도핑이 되지 않는다.When the pressure of the nitrogen gas is less than 1 atm, it is difficult to form a beta (Ceta) SiC phase transformation, and at 100 atmospheres or more, the reaction sintered product is not smoothly doped with nitrogen.
다시 말해, 상기 질소 가스의 압력이 1기압 ~ 100기압에서는 베타(Beta) SiC 상변태가 우수하게 나타난다.In other words, the beta (Ceta) SiC phase transformation is excellent when the pressure of the nitrogen gas is 1 atm ~ 100 atm.
그리고, 전술된 상기 질소 도핑 공정은 실리콘 휘발 공정과 동일한 온도에서 수행하는 것이 바람직하다.In addition, the nitrogen doping process described above is preferably performed at the same temperature as the silicon volatilization process.
결국, 본 발명의 제 2 실시예에 따라 탄화 규소 발열체의 제조 방법은 질소를 도핑하여 휘발되지 못한 실리콘과 반응시킴으로써, 발열체에서 실리콘을 완전히 제거하여 전기 저항을 효율적으로 낮출 수 있을 뿐만 아니라, 탄화 규소 격자 내로 질소가 도핑되어 빠른 발열 속도, 상온/고온 간 낮은 비저항 변화로 전기 안전성 및 온도 제어 용이성과 과열 방지 특성을 갖는 우수한 발열체를 제조할 수 있는 장점이 있다.As a result, according to the second embodiment of the present invention, the method for manufacturing a silicon carbide heating element reacts with silicon that is not volatilized by nitrogen, thereby completely removing silicon from the heating element, thereby effectively lowering the electrical resistance, and silicon carbide. Nitrogen is doped into the lattice, there is an advantage that can be produced an excellent heating element having a fast heat generation rate, low specific resistance change between room temperature / high temperature, electrical safety, temperature control ease and overheating prevention properties.
도 3은 본 발명의 제 2 실시예에 따른 탄화 규소 발열체를 제조하는 방법에서 적용된 열처리 공정 그래프로서, 탄화규소 분말과 탄소 분말이 혼합된 혼합물이 성형된 성형물에 실리콘 분말을 뿌리고, 그 성형물을 1600℃에서 30분 동안 반응 소결시킨다.3 is a graph showing a heat treatment process applied in a method of manufacturing a silicon carbide heating element according to a second embodiment of the present invention, in which a silicon powder is sprayed onto a molded article in which a mixture of silicon carbide powder and carbon powder is mixed, and the molding is 1600 The reaction is sintered at 30 캜 for 30 minutes.
그 후, 1700℃로 승온시킨 후, 1700℃에서 30분 동안 상기 반응 소결물을 열처리하여 상기 반응 소결물에 잔류되어 있는 실리콘을 휘발시켜 제거한다.Thereafter, after the temperature is raised to 1700 ° C., the reaction sintered product is heat-treated at 1700 ° C. for 30 minutes to volatilize and remove the silicon remaining in the reaction sintered product.
그 다음, 1700℃에서 상기 반응 소결물에 질소를 도핑한다.The reaction sinter is then doped with nitrogen at 1700 ° C.
상기 반응 소결물에 질소를 도핑하는 것은 상기 반응 소결물을 1시간 30분동안 질소 처리하는 것이다. Doping nitrogen into the reaction sintered material is nitrogen treatment of the reaction sintered material for 1 hour and 30 minutes.
도 4는 본 발명에 따른 탄화 규소 발열체를 제조하는 방법에서 양산된 시편의 XRD(X-ray diffraction) 분석 그래프로서, 도 4의 'RS'는 반응소결 시편에 대한 분석 그래프이고, 'EV'는 휘발처리된 시편에 대한 분석 그래프이고, 'NI'는 질소 도핑된 시편에 대한 분석 그래프이다.4 is an X-ray diffraction (XRD) analysis graph of the mass produced in the method for producing a silicon carbide heating element according to the present invention, 'RS' of Figure 4 is an analysis graph for the reaction sintered specimen, 'EV' Analysis graph for volatilized specimens, 'NI' is the analysis graph for nitrogen doped specimens.
XRD 분석 그래프의 2θ = 47.3°와 56.1°에서, 질소 도핑된 시편(NI)에서는 실리콘 결정상이 전혀 나타나지 않아, 질소 도핑으로 잔류 실리콘이 완전히 제거되 었음을 알 수 있다.At 2θ = 47.3 ° and 56.1 ° of the XRD analysis graph, the nitrogen doped specimen (NI) did not show any silicon crystal phase, indicating that the residual silicon was completely removed by nitrogen doping.
그리고, 2θ = 47.3°와 56.1°에서 휘발처리된 시편(EV) 및 반응소결 시편(RS)에서 피크(Peak)가 나타났는데, 휘발처리된 시편(EV)의 피크는 반응소결 시편(RS)의 피크보다 강도가 상당히 약해진 것으로 나타났다.At 2θ = 47.3 ° and 56.1 °, peaks were observed in the volatilized specimens (EV) and reaction sintered specimens (RS), and the peaks of the volatilized specimens (EV) were measured in the reaction sintered specimens (RS). The intensity was found to be significantly weaker than the peak.
그러므로, 휘발 처리 공정에서 실리콘이 상당히 제거되었고, 질소 도핑 공정을 수행하면, 휘발 처리 공정에서 휘발되지 않은 실리콘이 완전히 제거할 수 있음을 확인할 수 있다. Therefore, it was confirmed that the silicon was significantly removed in the volatilization process, and the nitrogen doping process could be completely removed in the volatilization process.
도 5는 본 발명에 따라 질소 도핑된 시편의 투과 전자 현미경(TEM) 및 SAD(Selective Area Diffraction) 분석 결과의 사진으로서, 투과 전자 현미경으로 촬영한 질소 도핑된 시편의 사진에서 화살표 머리 부분의 SAD를 분석한 결과, 도 5의 상측에 도시된 바와 같이, 회절 패턴이 질화 규소 상으로 나타났다.FIG. 5 is a photograph of a transmission electron microscope (TEM) and a selective area diffraction (SAD) analysis result of a nitrogen doped specimen according to the present invention, and shows the SAD of the head of the arrow in the photograph of the nitrogen doped specimen taken with a transmission electron microscope. As a result of the analysis, as shown in the upper side of FIG. 5, the diffraction pattern appeared as a silicon nitride phase.
그리고, 도 6은 도 5의 화살표 방향으로 EDS(Energy Dispersive Spectroscopy) 성분 분석 결과 그래프이며, EDS 성분 분석 결과 화살표 머리 부분에서 질소 농도가 증가한 것을 알 수 있다.And, Figure 6 is a graph of the results of EDS (Energy Dispersive Spectroscopy) component analysis in the direction of the arrow of Figure 5, it can be seen that the nitrogen concentration increased in the head of the EDS component analysis results.
도 7은 본 발명에 따른 탄화 규소 발열체를 제조하는 방법에서 양산된 시편의 온도 증가에 따른 비저항 변화를 측정한 그래프로서, 반응소결 시편(RS)은 잔류 실리콘이 상당히 많이 있기 때문에 상당히 낮은 비저항을 갖고 있고, 온도의 증가에 따라 비저항이 증가하는 PTC(Positive Temperature Coefficient) 특성이 나타난 다.7 is a graph measuring the change in specific resistance according to the temperature increase of the mass produced specimen in the method of manufacturing a silicon carbide heating element according to the present invention, the reaction sintered specimen (RS) has a significantly lower resistivity because there is a considerable amount of residual silicon In addition, PTC (Positive Temperature Coefficient) characteristics that the specific resistance increases with increasing temperature appears.
그리고, 휘발처리된 시편(EV)은 실리콘이 휘발되어 제거되었기에, 반응소결 시편(RS)보다 잔류 실리콘이 적어 비저항이 상당히 증가되고, 새로이 생성된 반응소결 탄화규소의 전형적인 비저항 온도특성 변화인 NTC(Negative Temperature Coefficient)가 나타난다.In addition, since the volatilized specimen (EV) was removed by volatilization of silicon, the resistivity was significantly increased due to less residual silicon than the reaction sintered specimen (RS), and NTC (typical change in specific resistivity temperature characteristic of newly produced reaction-sintered silicon carbide) Negative Temperature Coefficient.
또, 질소 도핑된 시편(NI)은 질소 도핑에 의하여 잔류 실리콘이 완전히 제거되었음에도 불구하고 비저항이 감소하고, 비저항 온도특성이 PTC로 되돌아간 현상이 나타난다.In addition, although the nitrogen-doped specimens NI have completely removed residual silicon by nitrogen doping, the resistivity decreases and the resistivity temperature characteristic returns to PTC.
이는 질소가 탄화규소 격자 내에 도핑됨으로써, 유동 전하 운반자의 농도가 증가하여 나타나는 특성이다.This is a property of nitrogen being doped in the silicon carbide lattice, resulting in increased concentration of the flow charge carriers.
도 8a와 8b는 본 발명에 따른 탄화 규소 발열체 및 비교예의 탄화 규소 발열체로 제작된 가스 점화기의 온도 변화에 따른 저항 변화를 측정한 그래프로서, 먼저, 도 8a는 본 발명의 방법에서 제조된 탄화 규소 발열체로 제작된 가스 점화기의 온도 변화에 따른 저항 변화를 측정한 그래프이고, 'A' 곡선으로 측정되었다.8A and 8B are graphs of measurement of resistance change according to temperature change of a gas igniter manufactured from a silicon carbide heating element according to the present invention and a silicon carbide heating element according to a comparative example. First, FIG. 8A is a silicon carbide manufactured by the method of the present invention. It is a graph measuring the resistance change according to the temperature change of the gas igniter manufactured by the heating element, measured by the 'A' curve.
여기서, 본 발명의 방법에서 제조된 탄화 규소 발열체는 탄화규소 격자 내에 질소가 도핑되어 있다.Here, the silicon carbide heating element produced by the method of the present invention is doped with nitrogen in the silicon carbide lattice.
그러므로, 본 발명의 방법에서 제조된 탄화 규소 발열체로 제작된 가스 점화기에서는 측정 온도 구간(650℃ ~ 1150℃)에서 PTC 특성만 나타났다.Therefore, in the gas igniter manufactured by the silicon carbide heating element manufactured by the method of the present invention, only PTC characteristics appeared in the measurement temperature range (650 ° C to 1150 ° C).
그리고, 비교예의 탄화 규소 발열체는 조대입자와 미세입자의 표면 에너지 차이에 의해 2000℃ 온도에서 재결합하여 형성된 것이고, 질소는 도핑되어 있지 않다. In addition, the silicon carbide heating element of Comparative Example is formed by recombination at a temperature of 2000 ° C. due to the surface energy difference between the coarse particles and the fine particles, and is not doped with nitrogen.
이 비교예의 탄화 규소 발열체로 제작된 가스 점화기의 온도 변화에 따른 저항 변화를 측정한 그래프는 도 8b이고, 'B'곡선으로 측정되었다.The graph of measuring the resistance change according to the temperature change of the gas igniter manufactured by the silicon carbide heating element of this comparative example is FIG. 8B, and was measured by the 'B' curve.
이런 비교예의 탄화 규소 발열체로 제작된 가스 점화기는 770℃에서 NTC 특성에서 PTC 특성으로 변화되는 것이 관찰되었다.A gas igniter made of the silicon carbide heating element of this comparative example was observed to change from NTC characteristic to PTC characteristic at 770 ° C.
따라서, 본 발명의 방법에서 제조된 탄화 규소 발열체는 탄화규소 격자 내에 질소가 도핑됨으로써, 질소가 도핑되지 않은 비교예의 탄화 규소 발열체보다 유동 전하 운반자가 존재하여, 더 낮은 온도에서 빠른 온도 증가 특성을 갖고, 고온으로 갈수록 저항이 증가되어 자체적으로 과열되는 것을 억제할 수 있는 장점이 있는 것이다.Therefore, the silicon carbide heating element produced by the method of the present invention has a fast charge of temperature increase at a lower temperature due to the presence of flow charge carriers than the silicon carbide heating element of the comparative example without nitrogen doping, by nitrogen doping in the silicon carbide lattice As the temperature increases, the resistance increases, and thus, there is an advantage of suppressing overheating itself.
도 9는 본 발명에 따른 탄화 규소 발열체 및 비교예의 탄화 규소 발열체로 제작된 가스 점화기의 시간에 따른 표면 온도 변화를 측정한 그래프로서, 본 발명에 따른 탄화 규소 발열체로 제작된 가스 점화기와 비교예의 탄화 규소 발열체로 제작된 가스 점화기 각각에 115V의 전압을 인가한 후, 각 점화기의 표면 온도 변화를 시간에 따라 측정한 것이다.9 is a graph measuring the surface temperature change with time of the gas igniter made of the silicon carbide heating element and the silicon carbide heating element of the comparative example according to the present invention, the gas igniter made of the silicon carbide heating element according to the present invention and carbonization of the comparative example After applying a voltage of 115V to each gas igniter made of a silicon heating element, the surface temperature change of each igniter was measured with time.
이 측정 그래프를 보게 되면, 본 발명에 따른 탄화 규소 발열체로 제작된 가스 점화기의 측정 곡선(A1)과 비교예의 탄화 규소 발열체로 제작된 가스 점화기의 측정 곡선(B1)을 비교해보면, 본 발명에 따른 탄화 규소 발열체로 제작된 가스 점 화기의 측정 곡선가 비교예의 탄화 규소 발열체로 제작된 가스 점화기보다 발열 속도가 빠른 것을 알 수 있다.Looking at this measurement graph, comparing the measurement curve (A1) of the gas igniter made of the silicon carbide heating element according to the present invention and the measurement curve (B1) of the gas igniter made of the silicon carbide heating element of the comparative example, It can be seen that the measurement curve of the gas igniter made of the silicon carbide heating element is faster than the gas igniter made of the silicon carbide heating element of the comparative example.
그러므로, 본 발명에 따른 탄화 규소 발열체로 제작된 가스 점화기는 질소를 도핑함으로써, 발열 속도를 향상시킬 수 있는 것이다.Therefore, the gas igniter made of the silicon carbide heating element according to the present invention is capable of improving the exothermic rate by doping nitrogen.
본 발명은 구체적인 예에 대해서만 상세히 설명되었지만 본 발명의 기술사상 범위 내에서 다양한 변형 및 수정이 가능함은 당업자에게 있어서 명백한 것이며, 이러한 변형 및 수정이 첨부된 특허청구범위에 속함은 당연한 것이다.Although the invention has been described in detail only with respect to specific examples, it will be apparent to those skilled in the art that various modifications and variations are possible within the spirit of the invention, and such modifications and variations belong to the appended claims.
도 1은 본 발명의 제 1 실시예에 따라 탄화 규소 발열체의 제조 방법을 설명하기 위한 개략적인 흐름도1 is a schematic flowchart illustrating a method of manufacturing a silicon carbide heating element according to a first embodiment of the present invention
도 2는 본 발명의 제 2 실시예에 따라 탄화 규소 발열체의 제조 방법을 설명하기 위한 개략적인 흐름도2 is a schematic flowchart illustrating a method of manufacturing a silicon carbide heating element according to a second embodiment of the present invention.
도 3은 본 발명의 제 2 실시예에 따른 탄화 규소 발열체를 제조하는 방법에서 적용된 열처리 공정 그래프3 is a graph of a heat treatment process applied in a method of manufacturing a silicon carbide heating element according to a second embodiment of the present invention
도 4는 본 발명에 따른 탄화 규소 발열체를 제조하는 방법에서 양산된 시편의 XRD(X-ray diffraction) 분석 그래프Figure 4 is an X-ray diffraction (XRD) graph of the sample produced in the method for producing a silicon carbide heating element according to the present invention
도 5는 본 발명에 따라 질소 도핑된 시편의 투과 전자 현미경(TEM) 및 SAD(Selective Area Diffraction) 분석 결과의 사진5 is a photograph of the results of transmission electron microscopy (TEM) and selective area diffraction (SAD) analysis of nitrogen doped specimens according to the present invention.
도 6은 도 5의 화살표 방향으로 EDS(Energy Dispersive Spectroscopy) 성분 분석 결과 그래프FIG. 6 is a graph illustrating results of analysis of energy dispersive spectroscopy (EDS) in the direction of the arrow of FIG.
도 7은 본 발명에 따른 탄화 규소 발열체를 제조하는 방법에서 양산된 시편의 온도 증가에 따른 비저항 변화를 측정한 그래프Figure 7 is a graph measuring the change in resistivity with increasing temperature of the specimen produced in the method for producing a silicon carbide heating element according to the present invention
도 8a와 8b는 본 발명에 따른 탄화 규소 발열체 및 비교예의 탄화 규소 발열체로 제작된 가스 점화기의 온도 변화에 따른 저항 변화를 측정한 그래프8A and 8B are graphs of measurement of resistance change according to temperature change of a gas igniter manufactured from a silicon carbide heating element and a silicon carbide heating element of a comparative example according to the present invention;
도 9는 본 발명에 따른 탄화 규소 발열체 및 비교예의 탄화 규소 발열체로 제작된 가스 점화기의 시간에 따른 표면 온도 변화를 측정한 그래프Figure 9 is a graph measuring the surface temperature change with time of the gas igniter made of a silicon carbide heating element and the silicon carbide heating element of the comparative example according to the present invention
Claims (9)
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