Copper wire coated with cuprous oxide - esp. to obtain good adhesion when sealing the wire into glass

摘要

The copper wire or other semi-finished prod. is heated to a high temp. using a dose amt. of air, and is then immersed in water or an aq. borate soln. (a). The pref. plant consists of an inclined tubular furnace with its lwoer, outlet end immersed at 45-90 degrees w.r.t. the surface of a bath of water or soln. (a); a valve is used to control the supply of air to the furnace, in which the surface of the wire is oxidised to Cu2O, and the valve has a cross-section which is 0.5-5% of that of the furnace. On leaving the aq. bath, the wire travels through a drying oven, and the inlet end of the drying oven may be immersed in teh aq. bath. A coating of Cu2P provides a good seal between the Cu wire and the glass; adn a coating of borate prevents the Cu2O from oxidn. to CuO during storage of the wire before sealing into glass. CuO should not be present because it does not dissolve in the glass and therefore impairs the bond of glass to metal.