Effect of structural ordering on functional properties of Fe-19Ga alloy
ФИО: Емдади А.
Научный руководитель: к.ф.-м.н., проф Головин Игорь Станиславович
Институт: Институт экотехнологий и инжиниринга
Кафедра: Кафедра Металловедения цветных металлов
Академическая группа: МТМ-13-1
Thermal history dependence of phase constitution, magnetic domain structure, magnetic, and magnetostrictive properties in differently heat treated Fe–19Ga (at.%) galfenol samples has been studied. After annealing at 900°C for 3 h, samples were subjected either to water quenching or to furnace cooling. A single phase – solid solution of Ga in α-Fe (A2 structure) was recorded for water-quenched (WQ) sample. High resolution X-ray diffraction (XRD) around 81° shows the peak shoulder for furnace-cooled (FC) sample, which is ascribed to the formation of D03 ordered domains during slow cooling. Magnetic domain configuration studied by magnetic force microscopy (MFM) reveals that the WQ sample has regularly aligned stripe domain structure, while irregular maze-like domain structure was observed in the FC sample. Magnetostriction and magnetization measurements by vibrating sample magnetometer (VSM) at room temperature demonstrated that ordering leads to decrease in saturation magnetostriction, saturation magnetization and damping capacity in FC sample. Thermal history dependence of magnetic and magnetostrictive properties is analyzed on the basis of the A2 (disordered) → D03 (ordered) transformation. The temperature range of ordering (from 200 to 300°C) was found in quenched samples by several experimental methods: DSC, internal friction and modulus, dilatometry and hardness tests.