Abstract:
Produit fritté présentant une masse volumique relative supérieure à 97% et constitué par: -plus de 92% poids de carbure de silicium, -entre 0,5 et 8% poids d'une phase secondaire amorphe comprenant les éléments O, Si et un ou deux éléments choisis parmi Al et Y, -moins de 2% d'autres éléments, présents dans ledit produit sous forme d'une phase supplémentaire ou d'impuretés inévitables, dans lequel le carbure de silicium est présent sous forme de grains cristallisés et dans lequel ladite phase secondaire est amorphe et localisée essentiellement aux joints des grains de carbure de silicium.
Abstract:
Laboratory heat press consists of furnace part equipped with dilatometer which is placed beneath removable double-acting pneumatic cylinder anchored on four shafts, of power supply and of computer which regulates process and collects data, while in the working space is situated graphite press die with sample, which is placed on sliding piston holder and the device is equipped with control electronics. Heating equipment is graphite element, and around the element are situated graphite shields made from solid graphite and graphite wool insulation. Outer shell of furnace and both flanges are water cooled. Flanges are equipped with holes for thrust pistons and the furnace shell contains hole for connecting the vacuum pump and hole for installation of the pyrometer. Graphite pressing die with sample is equipped with pistons, which are influenced by power from double-acting pneumatic cylinder, while on the both graphite pistons are graphite radiative rings and between them is graphite wool.
Abstract:
The invention relates to a method for assembling at least two refractory ceramic parts by means of spark plasma sintering, each of said parts having at least one surface to be assembled by means of spark plasma sintering, comprising the following steps in which: the surfaces of the parts to be assembled are brought into contact with one another with nothing added therebetween, an assembly pressure of between 1 and 200 MPa is applied to the parts, a pulsed electric current with a strength of between 500 and 8000 A is applied to the parts so as to raise the temperature thereof to an assembly temperature of at least 1300°C, the electric current and the pressure are removed simultaneously and the parts are cooled, and the assembled parts are recovered.
Abstract:
In a process for fabricating electrically insulating silicon carbide by means of liquid-phase sintering, wherein the sintering additives are added prior to sintering, the quantity of sintering additives, the sintering temperature and the duration of sintering are selected as process parameters. With the aid of these parameters, the quantity of intercrystalline phase remaining in the sintered silicon carbide is predetermined. This yields as end product a high-resistance electrical insulator.
Abstract:
Verfahren zur Herstellung eines Formkörpers, der wenigstens 85 Vol.-% kristallines Siliciumcarbid und maximal 15 Vol.-% Silicium enthält, umfassend die Schritte: • a) Bereitstellen eines pulverförmigen Gemisches, welches mindestens 60 Vol.-% amorphes Siliciumcarbid und maximal 40 Vol.-% Silicium mit einer Kristallitgröße von 3 - 50 nm enthält, • b) Formgebung des Gemisches durch • b1) Heißpressen oder • b2) Kompaktierung bei Raumtemperatur und nachfolgendem Sintern oder Heißpressen wobei das Sintern oder Heißpressen unter Inertgas oder Vakuum bei einer Temperatur von wenigstens 1400°C erfolgt. Das Volumenverhältnis SiC:Si im pulverförmigen Gemisch ist 95:5 - 99:1.
Abstract:
본 발명은 탄화규소 원료물질 및 소결조제 원료물질을 기계적 합금화(mechanical alloying) 공정에 의해 합성 분말로 제조하는 단계; 및 상기 합성 분말을 소결하는 단계를 포함하고, 상기 소결조제는 Al-C계, Al-B-C계 및 B-C 계로 이루어지는 군에서 선택되는 적어도 어느 하나인 것을 특징으로 하는 탄화규소 소결체의 제조방법 및 이에 따른 탄화규소 소결체에 관한 것으로, 저온에서 소결되면서도 치밀화되며, 높은 강도 및 전기전도성을 갖는 탄화규소 소결체를 제조할 수 있다.