▎ 摘　　要

NOVELTY - The powder metallurgy composite material has an aluminum sheet and a copper sheet which are sequentially laminated and compounded. A single-layer graphene is attached to the surface of the copper sheet. The outermost layer of the composite is a copper foil. USE - Powder metallurgy composite material. ADVANTAGE - In th method, by compounding the copper sheet and the aluminum sheet, the heat dissipation efficiency is improved, and the material cost is reduced. The graphene is vapor-deposited on the surface of the copper sheet, so that the oxidation of the surface of the copper sheet is prevented, and the heat conduction efficiency is improved. The heat conduction efficiency is improved by removing an oxide layer of the sheet blank. Processing and synthesizing in an oxygen-free environment avoids secondary formation of an oxide layer. By controlling the gas flow ratio, the deposition of the thin graphene is realized, and the heat conduction loss of the copper sheet and the aluminum sheet crystal boundary is made up. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a preparation method of the powder metallurgy composite material which comprises respectively carrying out low-energy ball milling on copper powder and aluminum powder to obtain smaller powder, and then respectively cold-pressing the powder into copper flake blanks and aluminum flake blanks; sequentially placing the sheet blank in acetone, ethanol, water and dilute hydrochloric acid in an oxygen-free box to remove a surface oxidation film by ultrasonic treatment, and then sequentially cleaning with water, ethanol and acetone and drying in the air; transferring the copper sheet blank into a tubular furnace, introducing methane, hydrogen and argon to perform in-situ vapor deposition of graphene, transferring the deposited graphene-copper sheet blank into an oxygen-free box to be stacked with the aluminum sheet blank at intervals, and then sealing, coating and discharging the box; and carrying out hot-pressing sintering in a sintering machine, introducing the mixture into a vacuum furnace to be densified and sintering in an argon atmosphere. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic flow chart for preparing the powder metallurgy composite material. Respectively carrying out low-energy ball milling on copper powder and aluminum powder to obtain smaller powder, and then respectively cold-pressing the powder into copper flake blanks and aluminum flake blanks (S1) Sequentially placing the sheet blank in acetone, ethanol, water and dilute hydrochloric acid in an oxygen-free box to remove a surface oxidation film by ultrasonic treatment, and then sequentially cleaning with water, ethanol and acetone and drying in the air (S2) Transferring the copper sheet blank into a tubular furnace, introducing methane, hydrogen and argon to perform in-situ vapor deposition of graphene, transferring the deposited graphene-copper sheet blank into an oxygen-free box to be stacked with the aluminum sheet blank at intervals, and then sealing, coating and discharging the box (S3) Carrying out hot-pressing sintering in a sintering machine, introducing the mixture into a vacuum furnace to be densified and sintering in an argon atmosphere (S4)