| The efffect of composition and different solidification rate on microstructure and magnetostiction of Fe-Ga alloy was studied systematically in this paper. Foundry alloy Fe100-xGax(x=17,19,21) and Fe83Ga15Al2 with different compositions were prepared by electric vacuum furnace melting. The Fe-Ga alloy under different solidification rate was prepared by zone melting directionally soldified technique. Draw the following results:The effect of compositions on Fe-Ga alloy magnetostiction is obvious. The magnetostiction acheieved extremum 53×10-6 and 37×10-6 under Ga content 17% and 21%, respectively. Basic structure of Fe-Ga alloy is disorder A2 phase, Ga atoms replace the Fe atoms, and engender lattice distortion for occupying different places. The different phase of compositions Fe-Ga alloy was formed by different placeholder form of Ga.Fe-Ga alloy by zone melting directionally solidified, the size of grain increased obviously, and as reducing of solidification rate, the grain elongated along the axial and the size of it increased either. When the solidification rate is 5μm/s, the structure of Fe-Ga alloy is composed of large size columuar crystals, which preferred growth along directional solidification direction. Under the higher of solidification rate, the grain has no preferred orientation, The strongest peak of X-ray diffraction is (110), But when the solidification rate reduced to 10μm/s and 5μm/s, the axial preferred orientation changed from <110> orientation to <100> orientation. The axial preferred orientation of the Fe-Ga alloy with the solidification rate at 30μm/s is <110>.The magnetostriction of Fe-Ga alloy is slightly improved by zone melting directionally soldified technique. Low field response of cast and v=5μm/s are poor, while The saturation magnetostriction of Fe-Ga alloy with the rate of 5μm/s reached to the maximum in 86×10-6. Compared to v=5μm/s, the Low field response is fast and the saturation magnetostriction is slightly lower, which is 63×10-6.In the cast of Fe83Ga15Al2 alloy, the saturation magnetostriction reduced to 8×10-6 for destroying Ga-Ga atom clusters in replacement solution. After zone melting directionally solidified, the size of grain is increased, the number of grain boundaries are reduced, and is composed of large size columuar crystals along the axial as reducing of solidification rate. The magnetostriction of Fe83Ga15Al2 alloy substantially increased, the Low field response is fast by zone melting directionally soldified technique. The saturation magnetostriction of it with the rate of 10μm/s reached to the maximum in 53×10-6. The content ofλis 50×10-6 with the rate of 300μm/s. But the Low field response is fast, reached to the maximum in 50KA/m.
|
PDF Full Text Request