Inhibition force of precipitates for promoting abnormal grain growth in magnetostrictive Fe83Ga17-(B,NbC) alloy sheets

Abstract

Inhibition force of precipitate particles for promoting abnormal grain growth in magnetostrictive Fe83Ga17-(B,NbC) alloy sheets was investigated in this study. After a continuous heating and a high-temperature annealing, the Fe83Ga17 + 0.5 at% B alloy sheets do not occur significant abnormal grain growth. Correspondingly, textures of {111} and {100} in addition to the Goss texture are obtained in the final annealed alloy sheets. By contrast, after the same annealing processes, the size of {110} textured grains is very large in the final annealed Fe83Ga17 + 0.5 at% NbC alloy sheets due to the abnormal grain growth, which results in a sharp Goss texture. BN precipitates were introduced into Fe83Ga17 + 0.2 at% B alloy sheets by nitriding annealing at 800 °C for 2 min under NH3 atmosphere. The abnormal grain growth of Goss grains is achieved in 0.2 at% B-doped Fe83Ga17 alloy sheets after a high-temperature annealing, which is attributed to the enhanced inhibition force by introducing BN precipitates. During the recrystallization annealing process, Fe2B precipitates is easy to coarsen and decompose at high temperature due to the low thermal stability, resulting in a decrease or even disappearance of the inhibition force. For NbC and BN precipitates, the thermal stability and hardness of particles are both better than those of Fe2B precipitates, leading to strong inhibition force. Because of the preferred Goss texture, the magnetostriction of 2.05 × 10−4 and 1.81 × 10−4 is obtained in the secondary recrystallized Fe83Ga17 + 0.5 at% NbC and Fe83Ga17 + 0.2 at% B alloy sheets, respectively.