High-efficiency and short-process method for preparing a high-strength and high-conductivity copper alloy

A method for preparing a copper alloy, comprising the following steps:

• (a) performing horizontal continuous casting to obtain an as-cast primary billet of copper alloy, wherein the alloying elements in the obtained as-cast primary billet being in a supersaturated solid solution state without precipitation strengthening;
• (b) after peeling the as-cast primary billet obtained in step (a), directly performing continuous extrusion, cold working and aging annealing treatment to obtain a copper alloy, and keeping the alloying elements of the billet in supersaturated solid solution without precipitation strengthening during the process of continuous extrusion;
• wherein the horizontal continuous casting is implemented as follows:
• installing at least one multi-channel water-cooled crystallizers under the side of the holding furnace, the multi-channel water-cooled crystallizers being provided with three groups of independent cooling units along the extraction direction of the primary billet to realize multi-channel water inflow and multi-channel water outflow, and adopting a reverse cooling method, to allow the first group of cooling units to be closest to the holding furnace;
• making the temperature of the water inlet of each group of cooling units lower than 20° C., and controlling the temperature gradient of the three groups of cooling units by the following method:
• the water flow V3 of the third group of cooling units and the primary billet cross-sectional area S should satisfy 0.5 L/(min·mm2)<V3/S<2 L/(min·mm2), and the water flow V2 of the second group of cooling units and the water flow V1 of the first group of cooling units are determined according to the principle of V1:V2:V3=1.5:1.2:1;
• providing electromagnetic induction coils on the outer walls of the water cooling jackets of the first and second groups of cooling units of the multi—channel water-cooled crystallizer to achieve electromagnetic stirring, the electromagnetic stirring method being rotary stirring, and the current frequency being set to 2 to 500 Hz;
• controlling the primary billet cross-sectional area S to be 2000 to 50 mm2, and the extraction speed and the primary billet cross-sectional area satisfying 0.5 mm·min≤S/v≤20 mm·min;
• providing a water curtain spray cooling device within 1000 mm outside the outlet of the multi-channel water-cooled crystallizer to cool the primary billet, the spray device adopting an atomizing nozzle, and the nozzle interval being 10 to 20 mm, setting the number according to the size of the billet, such that the distance between the nozzle and the surface of the billet is 10 to 50 mm and the water pressure is 0.5 to 0.8 MPa, so as to obtain the primary billet whose alloying elements are all in a supersaturated solid solution state.