▎ 摘　　要

NOVELTY - Composite silicon carbide ceramic powder comprises 90-98 wt.% carbon nano-powder master batch and 2-10 wt.% additive, where additive comprises carbon nano powder, carbon nano tube and multi-wall graphene. USE - Composite silicon carbide ceramic powder used for preparing ceramic separating valve (claimed), which is used in a medical device such as oxygen generator. ADVANTAGE - The method enables to prepare composite silicon carbide ceramic powder, which has high toughness and strength, effectively resist external force, prevent further expansion of the crack to improve the fracture toughness of the complex phase ceramic, and improve the mechanical performance of the ceramic. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a method for preparing a ceramic separation valve, which involves: (a) mixing and dispersing the composite silicon carbide ceramic powder to obtain mixed powder; (b) pressing and forming mixed powder by bidirectional dry pressing to obtain blank; (c) heating blank in an inert gas atmosphere and maintaining the temperature at 2000-2200degrees Celsius for 1-4 hours to obtain sintered body; and (d) placing sintered body in hot isostatic pressing furnace, and performing heat treatment under an inert gas atmosphere at 1700-1900degrees Celsius and high pressure of 100-180 megapascal (MPa) for 30-120 minutes to obtain ceramic separation valve.