EXPERIMENTAL STUDY ON THE FABRICATION OF Ni-15Fe-4Mo SOFT MAGNETIC ALLOY (79HM) IN VACUUM INDUCTION MELTING FURNACE

Abstract

In this paper, technology for manufacturing soft magnetic alloy of the Ni-Fe-Mo system in the vacuum induction furnace (VIF) was studied. Through the process of calculating ingredient of materials, then melting and pouring into the mold, the authors have manufactured a Ni-15Fe-4Mo alloy with a composition equivalent to the 79HM permalloy soft magnetic alloy according to Russian standards. The melting and pouring temperature for this alloy is in the range from 1540^oC to 1560^oC. In the cast state, the microstructural features exhibit typical dendrites. After homogenization annealing at a temperature of about 1200^oC for a holding time of 4 hours, the alloy has non-dendritic structure. These results are the basis for further research to determine the properties of 79HM permalloy soft magnetic alloy for engineering applications.