Secondary Recrystallization Goss Texture Development in a Binary Fe81Ga19 Sheet Induced by Inherent Grain Boundary Mobility

Zhenghua He,Ning Shan,Yuhui Sha,Liang Zuo,Fan Lei,Yongkuang Gao,Fang Zhang

doi:10.3390/met9121254

Zhenghua He, Ning Shan + Show 5 more

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https://doi.org/10.3390/met9121254

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Journal: Metals	Publication Date: Nov 23, 2019
Citations: 5	License type: CC BY 4.0

Affiliation: Northeastern University, Chinese Academy of Sciences

Abstract

Secondary recrystallization Goss texture was efficiently achieved in rolled, binary Fe81Ga19 alloy sheets without the traditional dependence on inhibitors and the surface energy effect. The development of abnormal grain growth (AGG) of Goss grains was analyzed by quasi-situ electron backscatter diffraction (EBSD). The special primary recrystallization texture with strong {112}–{111}<110> and weak Goss texture provides the inherent pinning effect for normal grain growth by a large number of low angle grain boundaries (<15°) and very high angle grain boundaries (>45°) according to the calculation of misorientation angle distribution. The evolution of grain orientation and grain boundary characteristic indicates that the higher fraction of high energy grain boundaries (20–45°) around primary Goss grains supplies a relative advantage in grain boundary mobility from 950 °C to 1000 °C. The secondary recrystallization in binary Fe81Ga19 alloy is realized in terms of the controllable grain boundary mobility difference between Goss and matrix grains, coupled with the orientation and misorientation angle distribution of adjacent matrix grains.

Highlights

Giant magnetostrictive Fe-Ga alloy (Galfenol) is a promising magnetostrictive material for sensors and actuators applied in complex and harsh conditions due to the excellent combined magnetostrictive and mechanical properties [1,2,3]
Micron-sized particles of NbC are added in an Fe-Ga alloy sheet to suppress the growth of primary grains, and on this basis, the abnormal grain growth (AGG) of Goss grains is achieved by the surface energy effect from sulfur alloying or H2 S atmosphere
Under the lack of additional in binary Fe-Ga alloy, the driving force for secondary recrystallization mainly originates from the pinning in binary Fe-Ga alloy, the driving force for secondary recrystallization mainly originates from inherent grain boundary characteristic in primary recrystallization

Summary

Introduction

Giant magnetostrictive Fe-Ga alloy (Galfenol) is a promising magnetostrictive material for sensors and actuators applied in complex and harsh conditions due to the excellent combined magnetostrictive and mechanical properties [1,2,3]. Micron-sized particles of NbC are added in an Fe-Ga alloy sheet to suppress the growth of primary grains, and on this basis, the abnormal grain growth (AGG) of Goss grains is achieved by the surface energy effect from sulfur alloying or H2 S atmosphere. Na et al [16,17] reported that nearly single-crystal Goss grains with magnetostriction coefficient of 300 ppm were developed in Fe81 Ga19 sheets by combining 1–2.5 mol.% NbC micron particles with an H2 S + Ar atmosphere. Yuan and Liu et al [18,19,20] obtained centimeters-sized Goss grains with a magnetostriction coefficient of 245 ppm at annealing atmosphere containing the sulfur element in Fe-Ga-based sheet added 0.1 mol.% NbC

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