Effect of Al substitution for Ga on magnetostriction enhancement by annealing of as-cast Fe–Ga–Al alloys under low magnetic fields

Abstract

Abstract Samples of Fe82Ga18-xAlx (1.5 £ x £ 15) alloys were prepared using a high vacuum arc melting system and homogenized at 1100 8C for 3 h, 1 000 8C for 120 h, and 730 8C for 168 h. The Fe82Ga18-xAlx(3 £ x £ 13.5) alloys were annealed at 550 8C 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 Fe82Ga15Al3sample was particularly large at 165%, and the Fe82Ga9Al9sample showed the highest magnetostrictive coefficient (up to 114 · 10-6) without compressive stress.