摘要:
The present invention is directed to bearings produced from a silicon nitride material. The silicon nitride material consists of a sintering aid selected from the group consisting of Al2O3 and Y2O3, silicon dioxide, and optionally, up to 10 mole %, based on the amount of silicon nitride, of an additive that reacts with silicon nitride, said additive selected from the group consisting of TiO2, WO3, MoO3 and mixtures thereof.
摘要翻译:本发明涉及由氮化硅材料制成的轴承。 氮化硅材料由选自Al 2 O 3 N 3和Y 2 O 3 3的烧结助剂组成, 基于氮化硅的量,至少10摩尔%的与氮化硅反应的添加剂,所述添加剂选自TiO 2,二氧化硅,以及任选的至多10摩尔% WO 3,MoO 3和它们的混合物。
摘要:
The invention concerns the field of ceramics and relates to modified composite silicon nitride powders as used, for example, for coating highly stressed components. It is the aim of the invention to provide modified composite silicon nitride powders and a process for their production by means of which silicon nitride coatings can be produced by prior art coating techniques. This aim is achieved by a modified silicon nitride powder in which silicon nitride particles are contained in an oxide-nitride or silicon binder matrix, where the binder matrix occupies 10 to 40% by volume of the total volume of the powder and the powder particle size d.sub.90 .ltoreq.100 .mu.m. The aim is also achieved by a process in which a mixture is made containing silicon nitride and/or silicon and one or more oxides or mixtures of oxides or containing silicon or silicon and silicon nitride, said mixture is homogenised and then granulated, subjected to single or multi-stage tempering in a nitrogen-containing atmosphere at a pressure of 0.5 to 100 bar ground.
摘要:
A boron suboxide composite material having improved fracture toughness consists of particulate or granular boron suboxide distributed in a binder phrase, such as AlxByOz, for example.
摘要翻译:具有改善的断裂韧性的低氧化硼复合材料由例如Al x B y O z等分布在粘合剂短语中的颗粒状或颗粒状的低氧化硼组成。
摘要:
The invention provides a boron suboxide composite material comprising boron suboxide and a secondary phase, wherein the secondary phase contains a mixture of at least two metal oxides, neither of which is a boron-containing oxide. At least one of the oxides may be selected from oxides of elements of Groups IA, IIA, IIIA, and IVA of the periodic table. Also, at least one of the oxides may be a rare earth metal oxide selected from the oxides of scandium, yttrium, and elements of the ianthanide series. The secondary phase of the composite material may also contain a boride, and particularly a boride selected from the borides of transition metals of the fourth to eighth groups of the periodic table.
摘要:
Chemical thrusters convert chemical energy predominantly into thermal energy and further into kinetic energy. These conversions are lossy and typically limit the usable thrust to 40-70% of the chemical energy (rockets). The exit velocity is maximized by increasing the temperature. However, temperature cannot be increased at will and can increase losses. Thrusters also have limited controllability under changing external conditions. The options for isochoric or detonative combustion are limited. This concept is intended to increase efficiency and controllability. Through changes in catalytic loads and electromagnetic dose, combustion is increased and can be selectively regulated. Pressure/temperature are influenced and can be adapted e.g. to the changing external pressure. The achievable thrust increases due to the higher exit velocity. Further advantages exist. The geometry of combustion chambers can be optimized (e.g. smaller, more efficient). The concept is particularly promising for detonation engines or novel supersonic combustors.
摘要:
Self-ignited burns can be increased by stimulation. External ignition must often be carried out in the combustion chamber. Often an ignition nucleus is formed electrically. This has energetic disadvantages. Required internals can be disadvantageous. Ignitions with plasma torches also need fixed internals. Electromagnetically, however, the ignition field can be widened, the combustion rate increased and the temperature changed. Due to high electrical consumption, this effective ignition has not yet been advantageous for aerospace applications. This concept should be feasible with low electrical energy requirements. Sufficient electrical energy can be provided by turbopump, generator or thermocouple. For better coupling of electromagnetism, catalytic absorbers and possibly other particles are used. These lower the activation energy. Contactless ignition can be achieved using ceramics or metallic antennas. Ignition in the center of the combustion chamber at the highest pressures is particularly promising. The aim is to achieve combustion that is as directional as possible.
摘要:
System for chemical engine systems or air-breathing engine systems comprising: a catalytic combustion and/or addition of metallic additives, which can additionally adapt the combustion by homogeneous, respectively heterogeneous catalysts. The adaptation of combustion rate, combustion pressure, combustion temperature, latent heat and other conditions (e.g. heat reflections) can be used in a variety of technological ways. This enables optimization of combustion chamber geometry and, for example, reduction of profile losses. Lossy energy conversions are to be minimized, or specifically adapted (e.g. to a variable ambient pressure during vertical starts). To protect the adapted combustion, methods are named to avoid e.g. fouling, aging of the reactive surface, destructive pressure shocks and especially thermal damage. The potential through further technological additions, e.g. by means of contactless ignition or superordinate process concept is pointed out.
摘要:
The invention provides a boron suboxide composite material comprising boron suboxide and a secondary phase, wherein the secondary phase contains a boride. The boride may be selected from the borides of transition metals of the fourth to eighth groups of the periodic table. Particularly, the boride may be selected from the borides of iron, cobalt, nickel, titanium, tungsten, hafnium, tantalum, zirconium, rhenium, molybdenum or chromium. The boride also may be a platinum group metal boride, preferably palladium boride. The secondary phase also may contain one or more oxides.
摘要:
The invention relates to an abrasive compact comprising a mass of diamond particles and a silicon containing binder phase wherein the diamond particles are present in an amount less than 75 volume % and the binder phase contains less than 2 volume % unreacted (elemental) silicon. The invention further relates to a method of producing an abrasive compact including the steps of forming a feed diamond powder into a diamond preform, interposing a separating mechanism between the diamond preform and a silicon infiltrant source, heating the diamond preform and silicon infiltrant source until the infiltrant is molten and the preform and infiltrant are isothermal and allowing infiltration from the molten silicon infiltrant source to occur into the diamond preform.
摘要:
A water-bearing domestic appliance and method of operating a water-bearing domestic appliance, wherein the domestic appliance includes a water feed system that is controlled by a control device and that supplies a measured volume of water to the domestic appliance. The domestic appliance further includes a total water volume detection device to detect a total volume of water that is supplied via the water feed system to the domestic appliance during its service life.