Method for manufacturing copper alloy powder for metal AM

A method for manufacturing a copper alloy powder for a metal additive manufacturing, the method comprising:

• a casting step of manufacturing a copper alloy ingot with a continuous casting apparatus including a melting furnace, which melts a copper raw material consisting of high-purity copper having a purity of 99.99 mass % or more to obtain molten copper, a tundish, which hold the molten copper, a connecting pipe, which connects the melting furnace and the tundish to supply the molten copper to the tundish, an addition unit, which adds alloy elements of a copper alloy to the molten copper in the tundish to obtain a molten copper alloy, and a continuous casting mold to which the molten copper alloy is supplied;
• and
• an atomizing treatment step of powdering the copper alloy ingot by performing melting and decomposing by an atomizing treatment in an inert gas or a vacuum atmosphere using the copper alloy ingot as a raw material,
• wherein in the casting step, the copper alloy ingot is continuously manufactured with a continuous casting apparatus,
• in the casting step, the melting furnace, the connecting pipe, and the tundish are in a non-oxidizing atmosphere,
• an O concentration of the copper alloy ingot is set to 8 mass ppm or less, and an H concentration of the copper alloy ingot is set to 3 mass ppm or less, and an S concentration of the copper alloy ingot is set to 15 mass ppm or less,
• a total of the O concentration, the H concentration, and an S concentration of the copper alloy ingot is set to 20 mass ppm or less,
• in the copper alloy ingot, a total amount of an impurity element (excluding O, H, and S) other than Cu and the alloy elements is 0.04 mass % or less, and
• in the copper alloy powder obtained by the atomizing treatment step, a total amount of an impurity element (excluding O, H, S and N) other than the alloy elements is 0.07 mass % or less.