JPS54142124A - Dumet wire - Google Patents

Abstract

PURPOSE: To enhance the reliability of Dumet wire when in use by increasing the adhesion between it and borate layer by forming the coating copper layer of Dumet wire with an oxygen-free copper containing one or more of a specific amount of Sc, Y, Ce, and La.

CONSTITUTION: The oxygen-free copper 2 containing one or more of 0.01 to 1.5% Sc, 0.05 to 1.5% Y, 0.001 to 1.5% Ce, and 0.001 to 1.5% La is adhered to the surface of the Fe-Ni core wire 1 containing 41 to 48% Ni by a pressure welding method, a soldering method, etc., and then the wire is made into the 0.5 mm diameter copper-covered Fe-Ni alloy wire 4 by a repeated drawing and annealing operation. Then a Cu₂O layer is formed on the surface of the wire by heating it by an electric over or the gas burner 6 and then the wire is dipped in the borax solution 7 containing 50 to 500 g/l of borax and again heated by the heater 8 to form a borate layer composed mainly of Cu₂O on its surface. Thus, the bonding strength of the borate layer 3 becomes greater and thus the exfoliation of the borate layer 3 upon machining, rapid cooling, etc., can be suppressed.

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