TY - JOUR

T1 - Mechanochemical Synthesis of a Precursor for the Formation of a Magnetostrictive Functional Material Galfenol under Sintering Conditions

AU - Grigoreva, T. F.

AU - Kiseleva, T. Yu

AU - Kovaleva, S. A.

AU - Zholudev, S. I.

AU - Vosmerikov, S. V.

AU - Devyatkina, E. T.

AU - Grigorev, V. D.

AU - Lyakhov, N. Z.

N1 - This work was performed within the framework of state assignment no. 121032500062-4 of the Institute of Solid State Chemistry and Mechanochemistry of the Siberian Branch of the Academy of Sciences. Authors thank Moscow University Program of Development for scientific equipment technical support. Publisher Copyright: © 2021, Pleiades Publishing, Ltd.

PY - 2021/11

Y1 - 2021/11

N2 - The products of mechanochemical synthesis and subsequent sintering of the Fe–20 wt % Ga system are studied by X-ray diffraction, electron diffraction, Mössbauer spectroscopy, and transmission, scanning and optical microscopy. After mechanical activation for 2 min in planetary ball mill AGO-2, about 70% of Fe is preserved and the FeGa3 intermetallic compound appears. Sintering of the resulting Fe/FeGa3 mechanocomposite takes place with the participation of a liquid phase. In the compacted material, the crystallite size of iron halves and the level of microstraines decreases fivefold. A structure with grain sizes of 3–8 μm forms and the microhardness is 360 HV. A sharp change in the phase composition of the mechanocomposite is observed after mechanical activation for 60 min: the FeGa3 phase disappears, an Fe(Ga) solid solution with a high gallium content appears, and about 50% of Fe is retained. After mechanical activation for 120 min, a Fe3Ga/Fe(Ga)/Fe mechanocomposite forms (grain sizes are 4–6 μm, microhardness is ~780 HV), sintering of which proceeds according to a solid-phase mechanism. The sintered materials are ferromagnetic. For the materials sintered from precursors after activation for 2 and 120 min, the coercive force is 35 and 77 Oe, respectively, the saturation magnetization is Msat = 162 and 131 A m2 kg–1, and the residual magnetization is Mres = 2.8 and 2.1 A m2 kg–1.

AB - The products of mechanochemical synthesis and subsequent sintering of the Fe–20 wt % Ga system are studied by X-ray diffraction, electron diffraction, Mössbauer spectroscopy, and transmission, scanning and optical microscopy. After mechanical activation for 2 min in planetary ball mill AGO-2, about 70% of Fe is preserved and the FeGa3 intermetallic compound appears. Sintering of the resulting Fe/FeGa3 mechanocomposite takes place with the participation of a liquid phase. In the compacted material, the crystallite size of iron halves and the level of microstraines decreases fivefold. A structure with grain sizes of 3–8 μm forms and the microhardness is 360 HV. A sharp change in the phase composition of the mechanocomposite is observed after mechanical activation for 60 min: the FeGa3 phase disappears, an Fe(Ga) solid solution with a high gallium content appears, and about 50% of Fe is retained. After mechanical activation for 120 min, a Fe3Ga/Fe(Ga)/Fe mechanocomposite forms (grain sizes are 4–6 μm, microhardness is ~780 HV), sintering of which proceeds according to a solid-phase mechanism. The sintered materials are ferromagnetic. For the materials sintered from precursors after activation for 2 and 120 min, the coercive force is 35 and 77 Oe, respectively, the saturation magnetization is Msat = 162 and 131 A m2 kg–1, and the residual magnetization is Mres = 2.8 and 2.1 A m2 kg–1.

KW - coercive force

KW - gallium

KW - iron

KW - mechanochemical synthesis

KW - mechanocomposites

KW - Mössbauer spectroscopy

KW - residual magnetization

KW - saturation magnetization

KW - thermobaric sintering

KW - X-ray diffraction analysis

UR - http://www.scopus.com/inward/record.url?scp=85122918159&partnerID=8YFLogxK

UR - https://www.mendeley.com/catalogue/433be4b9-d9f8-3b64-b032-e07a3ded3143/

U2 - 10.1134/S0036029521110057

DO - 10.1134/S0036029521110057

M3 - Article

AN - SCOPUS:85122918159

VL - 2021

SP - 1433

EP - 1440

JO - Russian Metallurgy (Metally)

JF - Russian Metallurgy (Metally)

SN - 0036-0295

IS - 11

ER -