Abstract
It is known that a slow cooled iron-aluminium alloy containing about 12% aluminium has a high permeability. The study of this report was carried out with the intention of investigating how the magnetic properties such as initial and maximum permeabilities are changed when a part of aluminium of this iron-aluminium alloy is substituted by silicon. The iron-aluminium-silicon alloys containing 8 to 13% aluminium and 0 to 4% silicon were melted in vacuum in a high frequency furnace, and the casts were hot rolled into sheets, about 1 mm in thickness, in order to prepare ring-shape specimens. Magnetic properties of these annealed specimens were measured. Consequently, it was found that there existed a high maximum permeability (about 20,000) range in the vicinity of the composition of 88% iron and 0 to 2% silicon, and a very high permeability (initial permeability μ0=3,000∼5,000 and maximum permeability μm=40,000∼50,000) range in the vicinity of the composition of 9% aluminium and 3% silicon. Vickers hardness of the alloys near the composition that has the highest permeability is about 360, which indicates that these alloys are the hardest among the high permeability alloys found at present.
