摘要:
A method for forming a ceramic part with an internal structure includes aqueous slip-casting and a polystyrene foam insert. An aqueous slurry is poured over the insert to form a green body. The insert is shaped to produce the desired internal structure upon being encased by the slurry. The insert is then removed from the green body by dissolving it in trichloroethylene. Because the polystyrene foam does not expand when exposed to trichloroethylene and rapidly dissolves, build up of shrinkage stress in the green body is avoided. The green body is then sintered to produce the ceramic part with an internal structure.
摘要:
A protective barrier coating system including a diffusion barrier coating and an oxidation barrier coating and method for use in protecting silicon-based ceramic turbine engine components. A complete barrier coating system includes a thermal barrier coating of stabilized zirconia and an environmental barrier coating of an alloyed tantalum oxide. The oxidation barrier coating includes a layer of metallic silicates formed on a substrate of silicon nitride or silicon carbide to be protected. The oxidation barrier coating can include silicates of scandium, ytterbia or yttrium. The oxidation barrier coating may also include an inner layer of Si2ON2 between the diffusion barrier and the metallic silicate layer. The oxidation barrier coating can be applied to the substrate by spraying, slurry dipping and sintering, by a sol-gel process followed by sintering, by plasma spray, or by electron beam-physical vapor deposition. The diffusion layer of essentially pure Si3N4 can be applied to the substrate to prevent the migration of damaging cations from the protective layers to the substrate and is preferably formed by chemical vapor deposition. A method for protecting silicon based substrates can comprise a step of forming an oxidation barrier coating on a substrate, where a step of forming the oxidation barrier includes a step of sintering the oxidation barrier and substrate in a wet gas containing hydrogen.
摘要翻译:一种包括扩散阻挡涂层和氧化屏障涂层的保护性屏障涂层系统以及用于保护硅基陶瓷涡轮发动机部件的方法。 完整的阻隔涂层系统包括稳定的氧化锆的隔热涂层和合金化氧化钽的环境屏障涂层。 氧化阻挡涂层包括在待保护的氮化硅或碳化硅的衬底上形成的金属硅酸盐层。 氧化屏障涂层可以包括钪,镱或钇的硅酸盐。 氧化阻隔涂层还可以包括扩散阻挡层和金属硅酸盐层之间的Si 2 2 2 N 2的内层。 通过喷雾,浆料浸渍和烧结,通过溶胶 - 凝胶法烧结,通过等离子体喷涂,或通过电子束 - 物理气相沉积,可将氧化阻隔涂层施加到基材上。 可以将基本上纯的Si 3 N 4 N 4的扩散层施加到基底上,以防止损伤的阳离子从保护层迁移到基底,并且优选地由化学 气相沉积。 用于保护硅基基板的方法可以包括在基板上形成氧化阻挡涂层的步骤,其中形成氧化屏障的步骤包括在含氢的湿气中烧结氧化阻挡层和基板的步骤。
摘要:
A component comprising a silicon-based substrate and a braze-based protective coating disposed on the silicon-based substrate. The braze-based coating comprises a brazed layer, wherein the brazed layer comprises at least one intermetallic compound. A scale layer may be formed on the brazed layer. An environmental barrier coating may be disposed directly on the brazed layer or directly on the scale layer. A thermal barrier coating may be disposed on the environmental barrier coating. Methods for making a Si-based component having a braze-based protective coating are also disclosed.
摘要:
Vapor deposition precursors that can deposit conformal thin ruthenium films on substrates with a very high growth rate, low resistivity and low levels of carbon, oxygen and nitrogen impurities have been provided. The precursors described herein include a compound having the formula CMC′, wherein M comprises a metal or a metalloid; C comprises a substituted or unsubstituted acyclic alkene, cycloalkene or cycloalkene-like ring structure; and C′ comprises a substituted or unsubstituted acyclic alkene, cycloalkene or cycloalkene-like ring structure; wherein at least one of C and C′ further and individually is substituted with a ligand represented by the formula CH(X)R1, wherein X is a N, P, or S-substituted functional group or hydroxyl, and R1 is hydrogen or a hydrocarbon. Methods of production of the vapor deposition precursors and the resulting films, and uses and end uses of the vapor deposition precursors and resulting films are also described.
摘要:
A method for depositing an encapsulation layer onto a surface of polymeric fibers and ballistic resistant fabrics. More particularly, the atomic layer deposition of materials onto non-semiconductive polymeric fibers and fabrics, and to fabrics having an conformal encapsulation layer that has been applied by atomic layer deposition.
摘要:
Sintered silicon nitride products comprising predominantly β-silicon nitride grains in combination with from about 0.1 to 30 mole % silicon carbide, and grain boundary secondary phases of scandium oxide and scandium disilicate. Such products have high fracture toughness, resistance to recession, and resistance to oxidation at temperatures of at least 1500° C. Methods for preparing sintered silicon nitride products are also disclosed.
摘要:
A component comprising a silicon-based substrate and a braze-based protective coating disposed on the silicon-based substrate. The braze-based coating comprises a brazed layer, wherein the brazed layer comprises at least one intermetallic compound. A scale layer may be formed on the brazed layer. An environmental barrier coating may be disposed directly on the brazed layer or directly on the scale layer. A thermal barrier coating may be disposed on the environmental barrier coating. Methods for making a Si-based component having a braze-based protective coating are also disclosed.
摘要:
An apparatus and method for issue grouping of instructions in a VLIW processor is disclosed. There can be one, two, or three issue groups (but no greater than three issue groups) in each VLIW packet. In one embodiment, a template in the VLIW packet comprises two issue group end markers where each issue group end marker comprises three bits. The three bits in the first issue group end marker identifies the instruction which is the last instruction in the first issue group. Likewise, the three bits in the second issue group end marker identifies the instruction which is the last instruction in the second issue group. Any instructions in the VLIW packet falling outside the two expressly defined first and second issue groups are placed in a third issue group. As such, three issue groups can be identified by use of the two issue group end markers. In one embodiment, the template of the VLIW packet includes a chaining bit. The chaining bit is used to “chain” instructions appearing after the last instruction of the last issue group of a first VLIW packet to the instructions in the first issue group of a second VLIW packet. In one embodiment, a mask generation logic along with other logic blocks are utilized to generate an appropriate mask. The generated mask is used to pass through instructions in a VLIW packet which belong to a same issue group for execution in a same clock cycle.
摘要:
A monolithic silicon nitride ceramic is densified at temperatures lower than 2000.degree. C. and heat treated at temperatures greater than 2000.degree. C. in the presence of at least 6.5 w % of multi-component sintering aids. This monolithic silicon nitride has a highly acicular microstructure Chevron Notch fracture toughness greater than 9 MPa.multidot.m.sup.1/2, R-curve behavior, high Weibull modulus, excellent damage tolerance, high thermal conductivity, and other desirable properties.
摘要:
A method and superalloy component for depositing a layer of material onto gas turbine engine components by atomic layer deposition. A superalloy component may have a ceramic thermal barrier coating on at least a portion of its surface, comprising a superalloy substrate and a bonding coat; and aluminum oxide (Al2O3) layer may be deposited on top of an yttria-stabilized zirconia layer and form a bonding coat by atomic layer deposition. The yttria-stabilized zirconia layer may have a plurality of micron sized gaps extending from the top surface of the ceramic coating towards the substrate and defining a plurality of columns of the yttria-stabilized zirconia layer. Also, atomic layer deposition may be used to lay an aluminum oxide (Al2O3) layer over a tantalum oxide (Ta2O5) layer on a silicon-based substrate. Using atomic layer deposition to coat the gas turbine engine components permits conformal coating of the columnar surface to permit gap expansion and contraction without sintering of the columnar surface or spalling of the coating, and form an oxidation resistant bonding coat.
摘要翻译:一种用于通过原子层沉积将材料层沉积到燃气涡轮发动机部件上的方法和超合金部件。 超级合金部件可以在其表面的至少一部分上具有陶瓷热障涂层,其包括超合金基底和粘合涂层; 并且氧化铝(Al 2 O 3 3)层可以沉积在氧化钇稳定的氧化锆层的顶部上,并通过原子层沉积形成粘结层。 氧化钇稳定的氧化锆层可以具有从陶瓷涂层的顶表面朝向衬底延伸的多个微米尺寸的间隙并且限定多个氧化钇稳定的氧化锆层的柱。 此外,原子层沉积可以用于在氧化钽(Ta 2 O 3)上铺设氧化铝(Al 2 O 3 O 3)层, SUB> 5 sub>)层。 使用原子层沉积来涂覆燃气涡轮发动机部件允许圆柱形表面的共形涂覆以允许间隙膨胀和收缩,而不会烧结柱状表面或剥落涂层,并形成抗氧化粘合涂层。