Aluminium alloy intended especially for manufacture of castings of mold segments for molding pneumatic tires and heat treatment process of mold segment castings

摘要

The present invention provides an aluminium alloy containing 85.55 to 89.00 percent by weight Al; 8.5 to 10.00 percent by weight Si; 0.6 to 1.2 percent by weight Cu; 0.6 to 1.0 percent by weight Ni; 0.4 to 0.8 percent by weight Mn; 0.03 to 0.05 percent by weight Sr; at the most 0.4 percent by weight Mg; at the most 0.6 percent by weight Fe; at the most 0.1 percent by weight Ti; at the most 0.1 percent by weight Zn and at the most 0.05 percent by weight other additives individually, whereby the other additives amount to 0.15 percent by weight at the most. The invention also provides a heat treatment process of mold segment castings made of the above-described alloy, wherein the mold segment castings are heated to an annealing temperature of 520 degC and annealed for a period of 0.5 to 8 hours. Subsequently, they are cooled in water with temperature in the range of 50 to 60 degC and then exposed to ageing at a temperature of 170 degC for a period of 6 to 8 hours.