Process for the production of oxygen-free copper casting and moldings

Claim 1

A process for the production of oxygen-free copper castings and moldings, which contain 0.05 to 0.2% by weight of boron as a micro-alloy element, the steps consisting essentially of: melting oxygen-containing electrolytic copper in a crucible to produce a melt; covering the exposed surface of the melt with a protective layer; immersing an additive consisting essentially of 0.3-1% of a CaB 6 , calculated on the weight of said melt, and between 3 and 12.5% of carbon, calculated on the weight of said CaB 6 , in said melt, said additive being in the form of a powder having a mean grain size of 300 μm, said step resulting in the production of an oxygen-free, copper-boron binary alloy, which contains 0.5 to 0.2% by weight of boron as the micro-alloy element; cooling the melt; molding the cooled melt to yield a solid casting; solution annealing the casting for a time between about 30 to 600 minutes at a temperature in the range of about 800° C to 950° C; and aging the quenched annealed casting for an extended time between about 60 to 300 hours at a temperature in the range of about 200° C to 500° C.