Study on the melt-textured technique in a magnetic field for giant magnetostrictive materials R–Fe alloy

The melt-textured technique in a magnetic field for giant magnetostrictive materials TbFex and Tb0.3Dy0.7Fex (1.9 ⩽ x ⩽ 2) alloy was investigated. The cooling rate, melt temperature, and the chemical composition were found to influence the texture formation along the easy magnetic axis during crystallization in a field. The experiments showed that the 〈1 1 1〉 orientation of Tb0.3Dy0.7Fe1.9 and TbFe1.9 alloy was dominant in the samples when those alloys were solidified at a cooling rate of less than 0.8 °C/min from a temperature slightly above their melting point, respectively, while in a magnetic field of above 100 mT. However, with the Fe concentration increasing from x = 1.93, excessive RFe3 phases precipitate in the melt and degrade the orientation degree of the sample during the slow solidification. Therefore the chemical composition of Tb0.3Dy0.7Fex and TbFex alloy should be controlled within 1.90 ⩽ x ⩽ 1.93 for better orientation and comprehensive performance.