Effect Of Al Substitution For Ga On Magnetostriction Enhancement By Annealing Of As-Cast Fe-Ga-Al Alloys Under Low Magnetic Fields

Samples of Fe82Ga18-xAlx (1.5 <= x <= 15) alloys were prepared using a high vacuum arc melting system and homogenized at 1100 degrees C for 3 h, 1 000 degrees C for 120 h, and 730 degrees C for 168 h. The Fe82Ga18-xAlx (3 <= x <= 13.5) alloys were annealed at 550 degrees C for 15 min, while being exposed to a low magnetic field. The structure of the alloys was analysed by X-ray diffraction and optical microscopy. The magnetostriction coefficient of each of the samples was measured. It was found that the magnetostriction values of Fe82Ga18-xAlx (3 <= x <= 13.5) alloys were enhanced by magnetic field annealing. The magnetostrictive growth rate of the Fe82Ga15Al3 sample was particularly large at 165%, and the Fe82Ga9Al9 sample showed the highest magnetostrictive coefficient (up to 114 x 10(-6)) without compressive stress.