Crystallographic textures in rolled and annealed Fe-Ga and Fe-Al alloys

Abstract

The feasibility of obtaining [001] preferred texture in polycrystalline Fe 85 Ga 15 and Fe 85 Al 15 magnetostrictive alloys containing 1 mol pct NbC using a low-cost conventional thermomechanical processing approach is shown in this work. Thermomechanical processing conditions examined consisted of a sequence of hot rolling, two-stage warm rolling at 400°C with intermediate anneal at 900°C and texture anneal in the temperature range of 900°C to 1300°C for time periods up to 24 hours. Textures present prior to and after texture annealing were characterized using orientation imaging microscopy in a scanning electron microscope. In the case of Fe 85 Ga 15 alloy with 1 mol pct NbC, the deformation-induced texture after a two-stage warm rolling consists of mixed {100}Ͻ110Ͼ and {111}Ͻ110Ͼ type partial textures. Texture annealing of the Fe 85 Ga 15 alloy with 1 mol pct NbC at 1150°C for 2 hours changes the texture to a predominant texture that is close to {001}͗100͘. On increasing the annealing time to 24 hours, the texture shifts toward {110}Ͻ100Ͼ. While texture anneal at both 1150°C and 1300°C produces a [001] or near-[001] preferred orientation along the rolling direction in the Fe 85 Ga 15 alloy with 1 mol pct NbC, 1150°C-24 hour treatment was found to provide the strongest [001] orientation among the conditions examined. Similar trends are observed for the case of Fe 85 Al 15 alloy with 1 mol pct NbC.

Secondary recrystallization behavior in the rolled columnar-grained Fe–Ga alloys

“…Thermal mechanical processes involving deformation and recrystallization have been employed to produce rolled Fe-Ga sheets [8][9][10][11][12], and 〈001〉 orientation along the rolling direction (RD) is preferred to maximize the magnetostrictive performance. Up to now, the secondary recrystallization, also named by abnormal grain growth (AGG), of Goss oriented ({110}〈001〉) grains has been the most effective way to achieve the sharp 〈001〉 orientation and large magnetostriction along the RD in the rolled Fe-Ga sheets [13][14][15][16][17][18].…”

Deformation behavior and magnetostriction of polycrystalline Fe–Ga–X (X=B,C,Mn,Mo,Nb,NbC) alloys

“…3 Although the addition of V, Cr, Mn, and Mo reduced the magnetostriction 100 , compared to that observed in the single crystal Fe-Ga binary alloy, these alloying additions have been shown to improve the roll ability of Fe-Ga alloy and eliminate edge cracking. 5 In this work, in order to improve the roll ability and form a ͗100͘ preferred orientation, the influence of alloying additions such as B, C, Mn, Mo, Nb, and NbC on the deformation behavior and magnetostriction of Fe-Ga alloy was investigated. 5 In this work, in order to improve the roll ability and form a ͗100͘ preferred orientation, the influence of alloying additions such as B, C, Mn, Mo, Nb, and NbC on the deformation behavior and magnetostriction of Fe-Ga alloy was investigated.…”

Effect of Initial Oriented Columnar Grains on the Texture Evolution and Magnetostriction in Fe–Ga Rolled Sheets

“…In order to produce thin sheets with reasonable robustness and magnetostrictive properties, efforts have been made to produce the textured sheets by rolling and secondary crystallization processes [8][9][10][11][12]. Up to now, the secondary recrystallization, also named abnormal grain growth (AGG), of Goss-oriented ({110}<001>) grains has been considered as the most effective way to achieve the sharp <001> orientation along the rolling direction in the rolled Fe-Ga alloy sheets [13][14][15][16][17][18].…”