▎ 摘　　要

NOVELTY - Preparing composite powder involves placing chromium oxide powder, grinding ball, adhesive and dispersant in water medium for ball milling and mixing to obtain powder one, performing spray granulation, and filtering with filter of 40-120 microns to obtain powder two, where thickness of graphene nanosheet is 6-8 nanometer (nm), width is 10-25 microns, and purity is 99%. The obtained powders are mixed to obtain composite powder, where mass ratio of chromium dioxide to graphene in composite powder is 1:0.01-0.05. USE - Method for preparing composite powder used for preparing dynamic friction sealing coating (claimed) used in engine turbine pump end face dynamic sealing requirement of aerospace equipment. ADVANTAGE - The method enables to provide chromium oxide/graphene dynamic friction sealing coating with excellent fluidity and spraying performance, and reduced wear rate. The ratio of chromium oxide phase to graphene phase, coating porosity and microscopic morphology apperance in composite coating is easily regulated by controlling the ratio of chromium oxide to graphene spherical powder. The graphene reacts in plasma flame to generate impurities, which ensures that added graphene is uniformly distributed in chromium oxide coating based on original design. The chromium oxide/graphene dynamic friction sealing coating composite coating has a structure in which relatively loose graphene coatings are uniformly distributed in dense chromium oxide coating, and composite structure releases thermal stress of chromium oxide coating in the preparation process, and graphene significantly improves toughness of coating and greatly reduces risk of cracking of coating. The integrity of the coating is maintained and coefficient of friction is reduced. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for: (1) a method for performing dynamic friction sealing coating, which involves: (a) cleaning surface of substrate, and carrying out sandblasting treatment; (b) spraying composite powder on surface of substrate treated to form chromium oxide/graphene composite coating; and (c) grinding and finishing surface of chromium oxide/graphene composite coating to obtain dynamic friction sealing coating; and (2) a dynamic friction sealing coating, which comprises not less than 95 wt.% chromium oxide, 0.5-5 wt.% graphene, less than 1 wt.% impurities, and sum of the mass percentages of chromium oxide, graphene and impurities is equal to 100%.