EFFECTS OF CASTING CONDITIONS ON THE STRUCTURE AND MAGNETIC PROPERTIES OF THE Co-19 at.Al-6 at. W ALLOY

摘要

The Co-19 at.%Al-6 at.%W alloy was prepared by two methods of casting. We used arc melting under an argon atmosphere with casting into a copper water-cooled casting mold and induction melting furnace with casting into a ceramic Al_2O_3 mold. According to the X-ray and SEM analyses, phase compositions depend on the cooling rate of the ingot after melting. After arc melting, the cast alloy has a three-phase structure, consisting of γ cobalt (FCC), intermetallic phases CoAl (B2) type, and Co_3W (DO_(19)) type. After the induction melting, the alloy has a three-phase structure, consisting of γ cobalt (FCC), intermetallic phases CoAl (B2) type, and Co_7W_6 (μ) type. All phases in the investigated ternary alloy at the room temperature are ferromagnetic. Curie temperatures of all obtained phases were defined. It is shown that the magnetic properties of the studied alloy are typical for soft magnetic materials.