▎ 摘　　要

NOVELTY - A multi-order load-type graphene oxide hybrid copper-chromium electrical contact material comprises 0.3 wt.% graphene oxide, 1.5-3.5 wt.% nano-cerium dioxide particles loaded with 30% chromium on surface of graphene oxide, and remainder of copper and impurities. USE - Multi-order load-type graphene oxide hybrid copper-chromium electrical contact material. ADVANTAGE - The multi-order load-type graphene oxide hybrid copper-chromium electrical contact material has desired affinity between graphene oxide and copper matrix, interface bonding, and conductivity of graphene oxide. Rare earth element in the electrical contact material can enhance surface activity and interfacial adhesion of graphene, and improve overall performance of electrical contact material. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparation of the multi-order load-type graphene oxide hybrid copper-chromium electrical contact material, which involves weighing (i) high-purity graphite powder, concentrated sulfuric acid, sodium nitrate and potassium permanganate according to the dosage ratio of 1-1.5 g:25-30 ml:0.5-1 g:6-9 g, adding (ii) concentrated sulfuric acid, sodium nitrate and high-purity graphite powder to a three-necked flask, maintaining the temperature of the reaction system at 0-5 degrees C under ice-water bath, stirring for 25-40 minutes, adding potassium permanganate, stirring for 8-12 minutes, maintaining at 10-20 degrees C for 1.5-2.5 hours, maintaining at 30-40 degrees C for 2.5-3.5 hours, maintaining at 85-95 degrees C, adding deionized water and reacting for 25-35 minutes to obtain a reaction product, adding (iii) 30% hydrogen peroxide to the reaction product, stirring at 33 degrees C in water bath until the solution turns brownish yellow, adding diluted hydrochloric acid to a mixing system, homogenizing, performing centrifugal washing 15-25 times using water at 4000 rpm until no sulfate ions can be detected in the supernatant after centrifugation, adding deionized water, performing centrifugal washing 15-25 times using water, until the pH of the supernatant obtained after centrifugation is 5.5-6.5 until no chloride ions can be detected in the supernatant after centrifugation, precipitating at 70-90 degrees C and vacuum-drying for 20-30 hours to obtain graphene oxide, weighing (iv) graphene oxide, cerium nitrate hexahydrate and aqueous ammonia according to the dosage ratio of 20 mg:1 mmol:0.7-1.2 ml, adding graphene oxide and cerium nitrate hexahydrate to deionized water, ultrasonically-dispersing to obtain a suspension, transferring the suspension to a reactor, adding aqueous ammonia, reacting at 200-250 degrees C for 20-30 hours, performing centrifugal washing using deionized water and anhydrous ethanol and vacuum-drying obtained precipitate to obtain loaded graphene oxide, weighing (v) 30% chromium powder, 66.2-68.2% pure copper powder and 1.8-3.8% loaded graphene oxide, placing chromium powder and pure copper powder in a ball milling tank and ball milling for 3.5-4.5 hours to obtain a mixed metal powder, adding (vi) supported graphene oxide to deionized water, ultrasonically-dispersing to obtain a suspension, adding the mixed metal powder, mechanically stirring for 1.5-3 hours, transferring to a vacuum freeze dryer and freeze-drying for 20-30 hours to obtain a mixed powder, and transferring (vii) the mixed powder to a graphite mold, placing graphite mold in a sintering furnace with a vacuum of 0.06-1 Pa for vacuum hot-pressing sintering, controlling heating rate in the sintering furnace to 8-11 degrees C/minute, increasing the furnace temperature rises to 650 degrees C, controlling the uniaxial pressure on the graphite mold to 30 MPa, maintaining the pressure for 1 hour and releasing the pressure, continuously heating up to 950 degrees C, heat-preserving, cooling after 1 hour, and taking out the obtained product, when the temperature lowers to room temperature.