热处理对Fe-Ga合金磁致伸缩性能的影响

Influence of Heat Treatment on Magnetostriction Performance of Fe81Ga19 Alloy

采用真空感应熔炼炉制备了Fe81Ga19合金,对Fe81Ga19合金经不同工艺处理后的相组成、晶粒取向及磁致伸缩性能进行了研究。结果表明:将Fe81Ga19合金加热至1080℃,经0.5、1和1.5 h保温后淬火所得的相都为无序的A2相。随保温时间延长,择优取向逐渐变得不明显,合金的磁致伸缩性能逐渐下降;通过改变Fe81Ga19合金的冷却方式,可以获得不同的相结构。铸态和淬火态合金依然是无序的A2相,空冷处理后的合金中出现了LI2相,炉冷态的Fe81Ga19合金,除A2相之外,还析出了DO3相。这两种相都不利于合金性能提高,所以磁致伸缩系数相对较低。淬火处理抑制了DO3相的析出,所以淬火态的Fe81Ga19合金相比空冷和炉冷的合金磁致伸缩系数较大。

The phases,grain orientation and magnetostriction performance of Fe81Ga19 alloy fabricated by vacuum induction melting furnace were studied.Results show that after the Fe81Ga19 alloy is heated to 1080 ℃,for 0.5 h,1 h,1.5 h heat preservation,and then quenching in water,the phase is disordered A2 phase.With the increase of holding time,the preferred orientation gradually becomes unconspicuous,and the magnetostrictive properties of the alloy decrease gradually.Through changing the cooling mode,Fe81Ga19 alloy can obtain different phase structure.Disordered A2 phase still appears in the as cast and quenched alloys.LI2 phase appears in the alloy after air cooling treatment.After furnace cooling,both A2 phase and DO3 phase appear in Fe81Ga19.These two phases are not conducive to the properties of the alloy,so the magnetostrictive coefficient is relatively low.Quenching treatment inhibites the precipitation of DO3 phase,so compared with air cooling and furnace cooling Fe81Ga19 alloy,quenched Fe81Ga19 alloy has larger magnetostrictive coefficient.