Formation of magnetic castings - by cold forming followed by thermal treatment at 500 degrees Celsius in air

摘要

The mixture for a magnetic casting includes a powder of magnetic and/or magnetisable natural and a glass powder which softens at less than 500 deg.C. The grains of magnetic and/or magnetisable materials are isolated from each other in the casting. The casting is produced by dispensing the mixture in a liquid to obtain good mixing and the paste obtained is then dried and cold formed in a suitable mould. After removing from the mould it is placed in an oven at a temp. great enough for the glass grains to soften and fuse imprisoning the magnetic powder. Fabrication of magnetic tori used in transformers, loading coils, suppressors for thyristors, switches in light calibrators, electric motors etc. Thermal treatment of the cold formed magnetic articles takes place at a relatively low temp. (about 500 deg.C) and in air.