Transformation Points in High Permeability Alloy "Super Sendust"

Magnetization in "Super Sendust" alloys (1-4% Ni, 4-8% Si, 2-6% Al, balance Fe) depends to a great extent on composition and conditions of heat treatment. The alloy hardness, electrical resistivity, saturation magnetization, and crystal structure as functions of temperature and heat treatment were studied. Setting Si and Al contents at 6 and 4 percent and substituting 0-7% Ni for Fe, various material properties went through extreme at 3.2% Ni. Structural analyses revealed a shift from body-centered to face-centered cubic when the temperature was raised to 710°C. These and other abnormal changes in alloy properties are thought to be closely related to a DO3-type superlattice structure.