Abstract
The magnetostriction of iron-aluminium alloys has been measured by an apparatus designed by the present investigators in various longitudinal fields of less than 1200 Oersteds. The positive magnetostriction of iron gradually increases by the addition of aluminium, while the negative one decreases. All the alloys containing more than 5.90 percent of aluminium have only a positive magnetostriotion, and especially in the case of alloys containing more than 8.80 percent aluminium the magnetostriotion always increases with the magnetizing field or the intensity of magnetization; showing no maximum. The magnetostrictoin at a constant field of 1100 Oersteds shows a negative value, in the range of less than 5.3 percent aluminium content, while a positive value in the aluminium content above this percentage. And in the range of the aluminium content 11.5_??_13.2 percent the magnetostriction is very high; its highest value being 40×10-6 of 13.14 percent aluminium alloy. These alloys may be excellent magnetostriction materials for a supersonic oscillator and have been called “Alfer” by the present investigators.
