公开(公告)号：US5114749A

公开(公告)日：1992-05-19

申请号：US554697

申请日：1990-07-18

申请人： Hiroaki Nishio ,  Keiji Watanabe ,  Michitaka Sato

发明人： Hiroaki Nishio ,  Keiji Watanabe ,  Michitaka Sato

IPC分类号： C04B41/00 ,  C04B41/50 ,  C04B41/80 ,  C04B41/87

CPC分类号： C04B41/009 ,  C04B41/0072 ,  C04B41/5059 ,  C04B41/5066 ,  C04B41/80 ,  C04B41/87

摘要： A method for manufacturing carbon material having good resistance to oxidation, comprising coating carbon material, which is a sintered body or a porous body, with an inorganic polysilazane; heating the carbon material coated with the inorganic polysilazane in an inert atmosphere to form amorphous silicon nitride on the surface of the carbon material; and reheating the heated carbon material in a non-nitriding and non-oxidizing atmosphere, the amorphous silicon nitride being decomposed and silicon carbide being formed on the surface of the carbon material; the reheating being conducted at a temperature of 1300.degree. C. to 1900.degree. C. and the non-nitriding and non-oxidizing atmosphere having a partial pressure of nitrogen determined with reference to a graph wherein the abscissa is a temperature in .degree.C. and the ordinate is partial pressure of nitrogen in atmospheres, the partial pressure being defined within an area under a line connecting a first point corresponding to 1300.degree. C. and 0.1 atmospheres and a second point corresponding to 1900.degree. C. and 20 atmospheres.

公开(公告)号：US4909973A

公开(公告)日：1990-03-20

申请号：US68947

申请日：1987-07-01

申请人： Hiroaki Nishio ,  Michitaka Sato

发明人： Hiroaki Nishio ,  Michitaka Sato

IPC分类号： C01B21/06 ,  C01B21/064 ,  C01B21/068 ,  C01B21/072 ,  C01B21/076 ,  C01B31/30 ,  C01B31/36 ,  C01B35/04 ,  C04B35/56 ,  C04B35/565 ,  C04B35/58 ,  C04B35/584 ,  C04B35/626

CPC分类号： C04B35/65 ,  C01B21/062 ,  C01B21/064 ,  C01B21/0687 ,  C01B21/0728 ,  C01B21/0768 ,  C01B31/30 ,  C01B31/305 ,  C01B31/36 ,  C01B35/04 ,  C04B35/5611 ,  C04B35/563 ,  C04B35/565 ,  C04B35/58007 ,  C04B35/58014 ,  C04B35/58071 ,  C04B35/58078 ,  C04B35/583 ,  C04B35/584 ,  C01P2006/60 ,  C01P2006/80

摘要： A method for refining powders comprising the steps of: (a) adding polytetrafluoroethylene powders to non-oxide ceramic powders to form a mixture by mixing; and (b) heating the mixture in non-oxidizing atmosphere to convert oxides existing on the surface of the non-oxide ceramic powders into gaseous fluorides, and removing gaseous fluorides. The fluororesin is a polytetrafluoroethylene resin. The heating temperature in the non-oxidizing atmosphere is 500.degree. C. to 1300.degree. C.

摘要翻译： 一种精制粉末的方法，包括以下步骤：（a）将聚四氟乙烯粉末加入到非氧化物陶瓷粉末中以通过混合形成混合物; 和（b）在非氧化性气氛中加热混合物，将非氧化物陶瓷粉末表面上存在的氧化物转化为气态氟化物，并除去气态氟化物。 氟树脂是聚四氟乙烯树脂。 非氧化性气氛中的加热温度为500〜1300℃。

公开(公告)号：US4943403A

公开(公告)日：1990-07-24

申请号：US872398

申请日：1986-06-10

申请人： Tsuneo Miyashita ,  Hiroaki Nishio ,  Michitaka Sato

发明人： Tsuneo Miyashita ,  Hiroaki Nishio ,  Michitaka Sato

IPC分类号： B28B1/24 ,  B01D11/02 ,  B01D12/00 ,  B22F3/02 ,  B22F3/10 ,  B28B1/14 ,  B28B1/26 ,  C04B35/638

CPC分类号： C04B35/638 ,  B01D11/0203 ,  B22F3/1025

摘要： There is disclosed a method for eliminating an organic dispersion medium from a molded product obtained by plasticizing-molding or casting-molding of metallic and/or ceramic powders wherein the elimination is by extraction by liquid carbon dioxide at a temperature not lower than -30.degree. C. and not higher than -31.1.degree. C. The method prevents nonuniform volumetric decrease of the molded product to be otherwise caused by the extraction of the organic dispersion medium, while also making it possible to completely eliminate the organic dispersion medium without causing residual strain or deformation in the molded product.

摘要翻译： 公开了一种通过对金属和/或陶瓷粉末进行增塑成型或浇铸成型而得到的成型体中除去有机分散介质的方法，其中通过在不低于-30℃的温度下用液态二氧化碳进行萃取 C.并且不高于-31.1℃。该方法可防止成型产品的不均匀体积减少，否则由提取有机分散介质引起，同时也可以完全消除有机分散介质而不产生残余应变 或模制产品中的变形。

公开(公告)号：US5250242A

公开(公告)日：1993-10-05

申请号：US623452

申请日：1990-12-18

申请人： Hiroaki Nishio ,  Keiji Watanabe ,  Michitaka Sato

发明人： Hiroaki Nishio ,  Keiji Watanabe ,  Michitaka Sato

IPC分类号： C04B41/80 ,  C04B35/645 ,  C04B41/50 ,  C04B41/52 ,  C04B41/85 ,  C04B41/87 ,  C04B41/89

CPC分类号： C04B41/009 ,  C04B35/6455 ,  C04B41/5025 ,  C04B41/52 ,  C04B41/87 ,  C04B41/89

摘要： A method of producing a ceramic sintered body having a ceramic membrane which comprises a process of applying a precursor capable of converting into a ceramic membrane having a new function through heating onto at least a portion of a ceramic porous body to impart said function of the surface of the ceramic porous body, a process of applying a precursor capable of converting into a gas-impermeable membrane through heating over the whole surface of the porous body, a process of forming the gas-impermeable membrane by heating, a process of conducting hot isostatic pressing to the porous body, and a process of removing said gas-impermeable membrane. Ceramic sintered bodies having a dense ceramic membrane on the surface can be produced efficiently in very short processes.

公开(公告)号：US5091222A

公开(公告)日：1992-02-25

申请号：US586801

申请日：1990-09-24

申请人： Hiroaki Nishio ,  Michitaka Sato ,  Keiji Watanabe

发明人： Hiroaki Nishio ,  Michitaka Sato ,  Keiji Watanabe

IPC分类号： C04B41/87 ,  B22F3/26 ,  C04B35/622 ,  C04B35/645 ,  C04B41/45 ,  C04B41/81 ,  C23C24/00

CPC分类号： C04B41/009 ,  B22F3/26 ,  C04B35/622 ,  C04B41/4535 ,  C04B41/4584 ,  C04B41/81

摘要： A method for forming a ceramic film comprises the steps of boiling a solution containing ceramics, dipping a base material into the solution, taking the base material out of the solution and drying the base material taken out of the solution in the presence of vapor of said boiling solution. The solution is a solution, in which ceramics is dispersed or dissolved. The solution is a solution, in which a precursor of ceramics is dispersed or dissolved.

公开(公告)号：US5066438A

公开(公告)日：1991-11-19

申请号：US455034

申请日：1989-12-22

申请人： Michitaka Sato ,  Hiroaki Nishio

发明人： Michitaka Sato ,  Hiroaki Nishio

IPC分类号： C04B35/593

CPC分类号： C04B35/593

摘要： A method of producing a silicon nitride sintered body which comprises using an amorphous Si.sub.3 N.sub.4 powder having a mean particle size of 5 to 50 nm, a nitrogen content of 30 to 39 wt. %, an oxygen content of 1 to 10 wt. %, the sum of the nitrogen content and the oxygen content being 38 to 42 wt. % and an unavoidable impurities content of less than 500 ppm as the raw material to form a molded body, sealing the molded body in a capsule and treating it with HIP in the range of 1000.degree. to 1800.degree. C. and 1000 to 2000 atm until the density becomes 3.1 to 3.4 g/cm.sup.3. In the method of the invention, active surface energy of silicon nitride powder is utilized as the driving force for sintering due to using a super fine powder. The super fine powder improves sintering ability by uniform mixing. The sintering ability is further improved by substituting a suitable amount of the nitrogen in the silicon nitride with oxygen. By the above means, the sintering strength can be secured under not severe sintering conditions. As a result, a sintering aid can be omitted.

公开(公告)号：US5021213A

公开(公告)日：1991-06-04

申请号：US540555

申请日：1990-06-20

申请人： Hiroaki Nishio ,  Akira Kato ,  Michitaka Sato ,  Keiji Watanabe

发明人： Hiroaki Nishio ,  Akira Kato ,  Michitaka Sato ,  Keiji Watanabe

IPC分类号： B22F3/10 ,  B22F3/12 ,  B22F3/22 ,  B28B1/00 ,  B28B1/26 ,  B28B7/34 ,  C04B35/634 ,  C04B35/636 ,  C04B35/638

CPC分类号： C04B35/63416 ,  B22F3/1021 ,  B22F3/125 ,  B22F3/22 ,  B28B1/00 ,  B28B1/26 ,  B28B7/342 ,  C04B35/634 ,  C04B35/6342 ,  C04B35/6365 ,  C04B35/638 ,  C04B2235/483

摘要： In the method of invention, the formability is imparted to the slurry of a metal or ceramic powder by employing a porous mold and removing the dispersion medium through the evaporation or thermal decomposition thereof, or by using a silazane oil as the dispersion medium and curing it by heating. Since the phase change usually accompanying volume change does not occur in the dispersion medium, strain and deformation rarely occur in the molded body. As result, the sintered body obtained has high dimensional accuracy.

公开(公告)号：US5073330A

公开(公告)日：1991-12-17

申请号：US560679

申请日：1990-07-31

申请人： Hiroaki Nishio ,  Keiji Watanabe ,  Michitaka Sato

发明人： Hiroaki Nishio ,  Keiji Watanabe ,  Michitaka Sato

IPC分类号： B29C49/00 ,  B29C51/00 ,  B29C70/58

CPC分类号： B29C70/58 ,  B29C49/0005 ,  B29C51/002 ,  B29C2049/069 ,  B29K2083/00 ,  B29K2709/02

摘要： A method of molding polysilazane which includes heating a liquid sheet composed of liquid polysilazane alone or containing not more than 30 wt. % of a ceramic powder or a ceramic precursor to form a highly viscous sheet having a viscosity coefficient of 10.sup.4 to 10.sup.6 poise, fitting the highly viscous sheet to a forming mold, and heating to set the sheet. According to the method of the invention, molded bodies are easily obtained which have relatively uniform thickness, and are excellent in transferability, homogeneous and show less defects.

公开(公告)号：US4983368A

公开(公告)日：1991-01-08

申请号：US455013

申请日：1989-12-22

申请人： Michitaka Sato ,  Keiji Watanabe ,  Hiroaki Nishio

发明人： Michitaka Sato ,  Keiji Watanabe ,  Hiroaki Nishio

IPC分类号： C01B21/082 ,  C04B35/597

CPC分类号： C01B21/0826 ,  C04B35/597 ,  C01P2004/61 ,  C01P2004/62 ,  C01P2006/10 ,  C01P2006/80

摘要： A method of producing a .beta.-sialon fine powder which comprises using a silane compound represented by the general formula of SiH.sub.x Cl.sub.4-x (0.ltoreq.x.ltoreq.4) as a Si source, aluminum chloride as an Al source and an ether represented by the general formula of ROR' (R,R'=C.sub.y H.sub.2y+1, 1.ltoreq.y.ltoreq.5) as an oxygen source respectively, dissolving them in an organic solvent capable of dissolving them to obtain a solution, introducing ammonia gas into the solution to produce a precipitates, and burning the precipitates in a nonoxidative atmosphere. In the .beta.-sialon fine powder obtained by the method of the invention, respective elements of Si, Al, O and N are uniformly distributed in a chemical viewpoint. A high density high strength sintered body can be produced even at a relatively low temperature by using the .beta.-sialon fine powder.

公开(公告)号：US4719078A

公开(公告)日：1988-01-12

申请号：US907981

申请日：1986-09-16

申请人： Tsuneo Miyashita ,  Hiroaki Nishio ,  Michitaka Sato

发明人： Tsuneo Miyashita ,  Hiroaki Nishio ,  Michitaka Sato

IPC分类号： B22F3/10 ,  B22F3/12 ,  B22F3/14 ,  B22F3/15 ,  C04B35/645 ,  B22F1/00

CPC分类号： B22F3/1266 ,  C04B35/6455

摘要： A method of sintering compacts of metals, ceramics and the like in powder form. At least the surface portion of the compact is sintered in a plasma atmosphere having a pressure of 10 Torr or less thereby eliminating the open voids and then the compact is subjected to a hot isostatic press process.

摘要翻译： 以粉末形式烧结金属，陶瓷等的压块的方法。 至少在压力为10Torr以下的等离子体气氛中烧结该压块的表面部分，从而消除了开放空隙，然后对该压坯进行热等静压处理。