Abstract:
A porous polycarbosilane tube and a method for manufacturing the same is provided to control the thickness of tube wall freely due to high specific surface area of the wall and the developed pore structure and to ensure excellent high strength, heat resistance, corrosion resistance and environmental proofing property. A method for manufacturing polycarbosilane tube comprises a step for extruding polycarbosilane in a fibrous type; a step for heat-treating it in the oxidizing atmosphere and hardening from the surface of polycarbosilane to form a uncured part on the fibrous polycarbosilane central part; and a step for forming hollow by dissolving the uncured central part of the fibrous polycarbosilane with a polar solvent.
Abstract:
An isotropic carbon material with excellent friction stability and high density that is suitably used as machinery seals is provided, and a manufacturing method of the isotropic carbon material comprising heat-treating pitch, thereby controlling volatile content of the pitch to obtain self-sinterability, and adding anisotropic graphite powder to improve friction stability of the carbon material is provided. An isotropic carbon material comprises pitch of which a volatile content is controlled to 8 to 12% by weight through heat treatment. The isotropic carbon material further comprises 1 to 10% by weight of an anisotropic graphite powder relative to the pitch weight. The pitch has a volatile content controlled to 8 to 12% by weight by heat-treating the pitch at 460 to 500 deg.C for 4 to 6 hours. The isotropic carbon material has a density value of at least 1.8 g/cm^3 after graphitizing the isotropic carbon material. In a manufacturing method of an isotropic carbon material comprising pitch, the manufacturing method comprises the step of heat-treating the pitch at 460 to 500 deg.C for 4 to 6 hours to control a volatile content of the pitch to 8 to 12% by weight. The manufacturing method further comprises the step of powdering the pitch of which the volatile content has been controlled through the heat treatment process, molding the powder, and carbonizing and graphitizing the molded powder. Further, the heat-treating step is performed by stirring the pitch at 80 to 120 rpm under an inert condition.
Abstract:
본발명은단순한공정의수행만으로도높은치밀화효율을발현할수 있고우수한물성을발현하는세라믹섬유를제조할수 있어생산성및 경제성이향상된이(異)종결정에의해강화된결정성세라믹섬유의제조방법및 그로부터제조된결정성세라믹섬유를제공한다. 또한, 본발명은고온에서의크리프에의한변형이억제되어고온내열성및 기계적물성이우수하며, 보다고온에서도우수한물성이발현및 유지될수 있는강화된결정성세라믹섬유를제공할수 있으며, 이를통해고온의극한환경에서사용되는부품등에널리응용될수 있다.