摘要:
The present disclosure relates to methods and systems for reducing silica recession of silicon-containing ceramics or silicon-containing ceramic composites, particularly those exposed to a combustion gas or to combustion gas environments, including those exposed to high temperature combustion gas environments. The methods and systems involve silicon-doping of compressed air and/or removal of moisture from compressed air prior to co-mingling the treated compressed air with the combustion gas to which the silicon-containing ceramics or silicon-containing ceramic composites are exposed.
摘要:
A refractory product includes CaO component-containing refractory particles and MgO component-containing refractory particles. The refractory material contains, a chemical composition measured after it has undergone heating in a non-oxidizing atmosphere at 1000° C., one or more of the following metal oxides B2O3, TiO2, V2O5, P2O5 and SiO2 in a total amount of 0.1 to 5.0 mass %, and free carbon in an amount of 2 to 35 mass %, with the remainder including CaO and MgO whose mass ratio (CaO/MgO) is in the range of 0.1 to 1.5. In microscopic observation performed at room temperature on the refractory material which has undergone the above heating, an inorganic film comprised of CaO and the one or more metal oxides is formed in at least each CaO surface of the refractory particles each containing either one or both of a CaO component and an MgO component, with a thickness of 0.1 to 25 μm.
摘要翻译:耐火材料包括含CaO组分的耐火材料颗粒和含MgO成分的耐火材料颗粒。 耐火材料含有在1000℃的非氧化性气氛中进行加热后测定的化学组成,一种或多种以下金属氧化物B 2 O 3,TiO 2,V 2 O 5,P 2 O 5和SiO 2的总量为0.1〜 5.0质量%,游离碳量为2〜35质量%,其余为CaO和MgO,质量比(CaO / MgO)为0.1〜1.5。 在经过上述加热的耐火材料的室温下进行的显微镜观察中,在耐火材料颗粒的至少每个CaO表面上形成由CaO和一种或多种金属氧化物组成的无机膜,每个CaO表面含有 CaO成分和MgO成分,厚度为0.1〜25μm。
摘要:
By inhibiting generation of particles, a carbon material and a method of manufacturing the carbon material are provided that can be used in the field of semiconductor manufacturing or the like, in which low dust emission is considered important.A carbon material having a chromium carbide layer formed on a surface of a carbon substrate. The chromium carbide layer is composed of Cr3C2. The carbon material can be manufactured through a first step of forming a chromium carbide layer containing a chromium carbide other than Cr3C2 on a surface of a carbon substrate, and a second step of heat-treating the carbon substrate under a reducing atmosphere to convert the chromium carbide other than Cr3C2 into Cr3C2.
摘要翻译:通过抑制颗粒的产生,可以提供碳材料和碳材料的制造方法,其可以用于半导体制造等领域,其中低尘发射被认为是重要的。 在碳基板的表面上形成有碳化铬层的碳材料。 碳化铬层由Cr3C2组成。 碳材料可以通过在碳基板的表面上形成含有Cr 3 C 2以外的碳化铬的碳化铬层的第一工序,以及在还原气氛下对碳基板进行热处理以将铬 Cr3C2以外的碳化物进入Cr3C2。
摘要:
Surface metallization technology for ceramic substrates is disclosed herein. It makes use of a known phenomenon that many metal—metal oxide alloys in liquid state readily wet an oxide ceramic surface and strongly bond to it upon solidification. To achieve high adhesion strength of a metallization to ceramic, a discrete metallization layer consisting of metal droplets bonded to ceramic surface using metal—metal oxide bonding process is produced first. Next, a continuous metal layer is deposited on top of the discrete layer and bonded to it using a sintering process. As a result a strongly adhering, glass-free metallization layer directly bonded to ceramic surface is produced. In particular, the process can be successfully used to metalize aluminum nitride ceramic with high thermal and electrical conductivity copper metal.
摘要:
Isopipes (13) for making a glass or a glass-ceramic using a fusion process are provided. The isopipes are made from a silicon nitride refractory material that is: (a) produced in block form in an atmosphere having a pO2 of less than 0.1 using less than 10 weight percent of one or more sintering aids, (b) machined into an isopipe configuration, and (c) exposed to a partial pressure of oxygen equal to or greater than 0.1 for a period of time and at a temperature sufficient to form a SiO2 layer (31) which exhibits substantially only a passive oxidation mechanism. The SiO2 layer (31) serves as a protective barrier for further oxidation of the silicon nitride during use of the isopipe (13). The isopipes (13) exhibit less sag during use than isopipes composed of zircon.
摘要:
A high-purity carbon fiber-reinforced carbon composite includes a matrix, a carbon fiber, and sulfur. The matrix includes a crystalline carbon-based powder and glassy carbon. A content of sulfur in the high-purity carbon fiber-reinforced carbon composite is 5 ppm by mass or less.
摘要:
A ceramic cutting tool configured as multiphase ceramic with an improved resistance to wear of the edge area or edge layer consists of a base ceramic and of a sacrificial phase as well as eventually additives and primary hard material phases and an eventually multilayered edge area or edge layer resistant to wear, hard, not deposited made of at least one hard material phase, whereby the edge area is intimately intergrown with the starting ceramic and which is formed by aging the starting ceramic in a defined atmosphere.
摘要:
A protective coating for use on a silicon-containing substrate, and deposition methods therefor. The coating has a strontium-aluminosilicate (SAS) composition that is less susceptible to degradation by volatilization and in corrosive environments as a result of having at least an outer surface region that consists essentially of one or more stoichiometric crystalline phases of SAS and is substantially free of a nonstoichiometric second crystalline phase of SAS that contains a substoichiometric amount of silica. The coating can be produced by carrying out deposition and heat treatment steps that result in the entire coating or just the outer surface region of the coating consisting essentially of the stoichiometric celsian phase.
摘要:
[Problems] To provide a method of producing, easily and in a high yield, a reformed aluminum nitride sintered body having very excellent light transmission property which can be favorably used as a light-transmitting cover particularly for light sources having high luminous efficiencies.[Means for Solution] An aluminum nitride sintered body having a concentration of metal impurities excluding aluminum of not more than 150 ppm, an oxygen concentration of not more than 0.5% by weight and a relative density of not less than 95% is used as a starting material. The aluminum nitride sintered body is heat-treated in an oxidizing atmosphere in a temperature region of 1400 to 2000° C. to increase the oxygen concentration by not less than 0.03% by weight.
摘要:
A process of obtaining silicon nitride (Si3N4) surface coatings on ceramic pieces and components by impregnation of the surfaces of the ceramic pieces with silicon powder suspensions with a particle size preferably less than 200 μm. The thickness of the coatings depends on the impregnation time and on the properties of the slip and the ceramic piece. The subsequent nitridation of the coating by thermal treatment at temperatures between 1300° C. and 1500° C. in N2 atmospheres leads to a continuous Si3N4 coating. The chemical stability and compatibility between Si3N4 and molten silicon enables its application in silicon metallurgy, in manufacturing crucibles for silicon fusion or for housing said molten silicon, in manufacturing pipes and chutes for its transport or in manufacturing different components for its subsequent purification.
摘要翻译:通过用粒度优选小于200μm的硅粉末悬浮液浸渍陶瓷片的表面来获得陶瓷片和部件上的氮化硅(Si 3 N 4)表面涂层的方法。 涂层的厚度取决于浸渍时间和滑动和陶瓷件的性能。 随后在N2气氛中在1300℃和1500℃之间的温度下热处理使涂层氮化,导致连续的Si 3 N 4涂层。 Si3N4和熔融硅之间的化学稳定性和相容性使其能够应用于硅冶金,制造用于硅熔化的坩埚或用于容纳所述熔融硅的制造管道和滑槽用于其输送或制造不同的组分以用于随后的纯化。