Dynamic precipitation and the resultant magnetostriction enhancement in [001]-oriented Fe-Ga alloys

Laser-beam powder bed fusion of magnetostrictive Fe81Ga19 alloys: parameter optimization, microstructural evolution and magnetostrictive properties

“…According to the standard diffraction pattern of bcc iron, disorder A2 phase structure was noted for both the gas-atomized powders and S2 through the observation of three peaks indexed to (110), (200), and (211) planes, suggesting no crystal structure changes before and after LPBF process. It should be pointed out that there was probably an overlap of A2 and D0 3 phase structures in XRD diffraction peaks due to the similar crystal structures of the two phases and similar scattering factors of Fe atoms and Ga atoms, and tiny amounts of D0 3 phase structure might be annihilated in the background of A2 phase structure [8,[52][53][54]. To sum up, the Fe 81 Ga 19 pre-alloyed powders with A2 disorder A2 phase structure were prepared by gas atomization, moreover, metastable A2 phase structure was still maintained in the LPBFed bulk alloys.…”

“…It is known that the magnetostrictive performances are intimately tied to the grain structures and phase compositions [8,59]. In Fe-Ga alloys, the presence of 〈001〉 oriented columnar grains and metastable A2 phase structure in the matrix was conducive to magnetostriction [9].…”

“…In prior researches, Chen et al [60] prepared Fe 81 Ga 19 sample with a magnetostriction of 86 ppm by using a rapid solidification technique. And many other methods, such as rolling [61] and casting [8], were also used to manufacture polycrystalline Fe-Ga alloy parts, however, which usually suffered from inferior magnetostrictive values and limited shapes and structures. In comparison, LPBF process offered high flexibility in the fabrication of diverse shapes and structures [62,63], thus facilitating the wider application of polycrystalline Fe-Ga alloys.…”

“…It is acknowledged that the magnetostrictive performances of Fe-Ga alloys are very sensitive to the grain structure and phase structure [6][7][8]. And previous studies [9,10] proved that the preferentially oriented grains and metastable A2 phase structure in Fe-Ga alloys played a crucial role for the enhancement of magnetostrictive strain.…”

Photoinduced deformation behavior of poly(aryl ether)s with different azobenzene groups in the side chain

“…Shape changes in polymer materials can be achieved under different stimuli, 1–3 such as light, 4 heat, 5 electricity, 6 magnetism, 7 pH, 8 or ionic strength. 9 Photoresponsive polymers 10,11 refer to macromolecules that undergo physical or chemical changes when exposed to specific wavelengths of light.…”