DISPERSION HARDENED COPPER ALLOY AS MATERIAL FOR MAKING CASTING MOLDS Russian patent published in 2007 - IPC B22C9/06 C22C9/06 C22F1/08 

FIELD: manufacture of casting molds of dispersion hardened copper alloys.

SUBSTANCE: material of casting mold contains next components, mass %: cobalt, 0.4 - 2%, possibly cobalt may partially changed by nickel in quantity up to 0.6%; beryllium, 0.1 - 0.55; zirconium, 0.03 - 0.5%; magnesium, 0.005 - 0.1% and if necessary no more than 15% at least of one element selected from group containing niobium, manganese, tantalum, vanadium, titanium, chrome, cerium and hafnium, copper, the balance, general additives and inevitable impurities. Casting mold is made by performing operations of casting, hot shaping, diffusion annealing at 850 - 980°C, cold shaping up to 30% and dispersion hardening at 400 -550°C for 2 - 32 h. Dispersion hardened copper alloy has in hardened state mean size of grains 30 -500 micrometers, hardness at least 185 HBW, conductance 30 - 36 M siemen/m, nominal limit yield at least 450 Mpa, elongation at rupture at least 12%. Such casting mold is made of alloy non-sensitive even at high casting speeds to variable temperature loads or having increased fatigue strength at working temperature.

EFFECT: improved qualities of casting mold.

6 cl, 3 tbl