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 coating powder based on chemically modified titanium suboxides, for use in various coating techniques. Coatings produced from this powder are characterized by high electroconductivity, good solid lubricating properties and resistance to wear. For these reasons, there are numerous possibilities of use of components which were coated by suitable processes with this powder, especially as functional layers for fuel cells in electrochemical installations, in the new car industry, in mechanical engineering and in other economic activities. The coating powder based on titanium suboxides having a defined defect structure is characterized in that it is modified by at least one metallic alloying element and described by general formula: Tin-2Me2O2n-1.
摘要翻译:一种基于化学改性的低价氧化物的涂料粉末,用于各种涂料技术。 由该粉末制成的涂层的特征在于高导电性,良好的固体润滑性能和耐磨性。 由于这些原因,使用通过合适的方法涂覆这种粉末的组分的许多可能性,特别是作为电化学装置中的燃料电池,新型汽车工业,机械工程和其它经济活动中的功能层。 具有确定的缺陷结构的基于低氧化钛的涂料粉末的特征在于其被至少一种金属合金元素改性并通过以下通式描述:Ti 2 n 2 Me 2 2n-2n-1。
摘要:
The invention relates to a coating powder and method for its production. Said powder can be used in many technical fields, specially in machine and vehicle construction in chemical and petro-chemical installations. This coating powder has a hardmetal-like microstructure and consists of two cubic hard material phases, each of them representing a nucleus-external surface structure of a hard material particle. The hard material phase in the nucleus contains mostly Ti and C and the hard material phase in the external surface mostly Ti, a second metal and C, which are embedded in a binder phase containing at least one or more elements such as Ni, Co and Fe. According to the invention, said coating powder is characterized by the fact that no additional alloying element exists either in the hard material phase, in the binder phase or in both phases simultaneously. According to the invention, the coating powder is produced by crushing and mixing and homogenizing the individual hard materials and the metal powder in an aqueous suspension in a ball triturator, which are later on granulated, sintered and processed using a grinding technique.
摘要:
The invention relates to bodies for separating out a component contained in a gas mixture. The gas mixtures may, for example, be crude gases which contain hydrocarbons, such as natural gas, or exhaust gas. According to the object which is set, the bodies according to the invention are intended to be able to separate components out of gas mixtures over longer periods of time with an approximately constant performance. The body according to the invention has regions which are active in the separation and are formed from a porous shell. These bodies which have a porous shell can be used in a device, and at least one bed formed from a bulk mass of these bodies may be present within a vessel, with the gas mixture being passed through this bed in order for the undesired component to be separated out. The invention is particularly advantageously suited to separating sulfur compounds out of gas mixtures.
摘要:
The invention relates to a method for dispersing and passivating particulate powders in water and aqueous media. It is particularly advantageously applicable in the handling and processing of non-oxidic powders, e.g., in the ceramic and hard-metal industry. In the method claimed auxiliaries are added due to the process. According to the invention this method is characterized in that polyvinylamines and/or the initial products thereof are used as these auxiliaries.
摘要:
Process for preparing granules of oxidic or nonoxidic metal compounds, characterized in that a dispersion which comprises water, oxidic or nonoxidic metal compounds and at least one dispersant is spray-dried,—where the proportion of oxidic or nonoxidic metal compounds is 40 to 70% by weight and the sum of the proportions of water and the particles is at least 70% by weight and—the particles have a BET surface area of 20 to 150 m2/g and a median of the particle size of less than 100 nm,—where the dispersant is present in the dispersion with a proportion of 0.25 to 10% by weight based on the oxidic or nonoxidic metal compounds and—where the spray-drying is performed by atomization with air in the cocurrent principle or fountain principle, and an air inlet temperature of 170 to 300° C. and an air outlet temperature of 90 to 130° C. are selected.
摘要:
A method of producing a plurality of discrete ultra-hard abrasive particles includes the steps of providing a plurality of granules, each comprising at least one ultra-hard abrasive particle, a precursor for the abrasive particle and a solvent/catalyst for the abrasive particle or precursor of such a solvent/catalyst, placing the granules with a separating medium between adjacent granules in the reaction zone of a high pressure/high temperature apparatus, subjecting the contents of the reaction zone to elevated temperature and pressure conditions at which the ultra-hard abrasive particle is crystallographically stable, recovering thus treated material from the reaction zone and removing the separating medium in the treated material to produce a plurality of discrete abrasive particles.
摘要:
A method is provided for producing a plurality of polycrystalline ultra-hard abrasive grit. The method includes the steps of providing a mass of ultra-hard abrasive particles or a mass of a combination of a precursor for such particles and a suitable solvent/catalyst, forming the mass into a plurality of green state granules, placing the granules with a separating medium between adjacent granules in the reaction zone of a high pressure/high temperature apparatus, subjecting the contents of the reaction zone to elevated temperature and pressure conditions which the ultra-hard abrasive particle is crystallographically stable, recovering the thus sintered material from the reaction zone and removing the separating medium in the sintered material to produce a plurality of crystalline abrasive grit. The ultra-hard abrasive is generally diamond or cubic boron nitride.
摘要:
The invention relates to bodies for separating out a component contained in a gas mixture. The gas mixtures may, for example, be crude gases which contain hydrocarbons, such as natural gas, or exhaust gas. According to the object which is set, the bodies according to the invention are intended to be able to separate components out of gas mixtures over longer periods of time with an approximately constant performance. The body according to the invention has regions which are active in the separation and are formed from a porous shell. These bodies which have a porous shell can be used in a device, and at least one bed formed from a bulk mass of these bodies may be present within a vessel, with the gas mixture being passed through this bed in order for the undesired component to be separated out. The invention is particularly advantageously suited to separating sulfur compounds out of gas mixtures.