Preparation method for ultrahigh-conductivity multilayer single-crystal laminated copper material, and copper material

A preparation method for an ultrahigh-conductivity multilayer single-crystal laminated copper material, comprising laminating multiple layers of single-crystal copper foils together to form a laminate, pressurizing and annealing the laminate as one piece by performing pressurizing and high-temperature annealing at the same time, or pressing the laminate as one piece by direct hot rolling, to fabricate the ultrahigh-conductivity multilayer single-crystal laminated copper material,

• wherein the method comprises steps of:
• (I) placing the laminate into a mechanical pressurizing device or a pressurizing mold in an annealing furnace, applying a static pressure of 0.5 MPa to 200 MPa, introducing, as protective gas, an inert gas at a flow rate of 200-2000 sccm and H2 gas at a flow rate of 20-500 sccm, and then elevating a temperature;
• or wrapping the laminate with a high-temperature-resistant protective outer cladding, then placing a resultant in front of hot rollers of a hot rolling mill in an atmospheric environment for rolling, and increasing a temperature of the hot rollers;
• (II) keeping the static pressure of 0.5 MPa to 200 MPa constant and keeping composition and flow rate of the introduced gas unchanged when a temperature of the annealing furnace is raised to 500-1100° C. to perform a pressurizing and annealing process;
• or keeping a pressure between the hot rollers of 0.5 MPa to 200 MPa constant when the temperature of the hot rollers is raised to 500-1100° C., and slowly passing the laminate wrapped with the high-temperature-resistant protective outer cladding through the hot rollers for hot rolling;
• and
• (III) reducing the temperature to room temperature, to obtain the ultrahigh-conductivity multilayer single-crystal laminated copper material when the pressurizing and annealing process or the hot rolling process ends.