The〈100〉oriented Fe83Ga17 alloy rods with various NbC contents less than 1at%were prepared by the directional solidification method at a growth rate of 720 mm·h^-1. Low NbC-content was found to affect the orien...The〈100〉oriented Fe83Ga17 alloy rods with various NbC contents less than 1at%were prepared by the directional solidification method at a growth rate of 720 mm·h^-1. Low NbC-content was found to affect the oriented grain growth and slightly improve the〈100〉ori-entation. Flat grain boundaries in the alloys with low NbC contents less than 0.2at%became greatly curved at higher NbC contents, and a large amount of Nb-rich precipitates were observed in the alloys with high NbC contents. Small amounts of NbC, less than 0.2at%, resulted in an increase in magnetostrictive strain due to the improvement of the〈100〉orientation, and a high magnetostrictive strain value of 335 ×10^-6 under a pre-stress of 15 MPa was obtained in the 0.1at%NbC-doped alloys. The magnetostrictive performance obviously decreased with the NbC addition higher than 0.5at%, and the strain sensitivity under no pre-stress was lower than that in the binary Fe？Ga alloy.展开更多
Inhibition force of precipitate particles for pro- moting abnormal grain growth in magnetostrictive Feg3Ga17-（B,NbC） alloy sheets was investigated in this study. After a continuous heating and a high-temperature ann...Inhibition force of precipitate particles for pro- moting abnormal grain growth in magnetostrictive Feg3Ga17-（B,NbC） alloy sheets was investigated in this study. After a continuous heating and a high-temperature annealing, the Fe83Gat7 ＋ 0.5 at% B alloy sheets do not occur significant abnormal grain growth. Correspondingly, textures of { 111 }〈112〉 and { 100}〈00l〉 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 Fe83Gaj7 ＋ 0.5 at% NbC alloy sheets due to the abnormal grain growth, which results in a sharp Goss texture. BN precipitates were introduced into Fes3Ga17 ＋ 0.2 at% B alloy sheets by nitriding annealing at 800℃ 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 decom- pose at high temperature due to the low thermal stability, resulting in a decrease or even disappearance of the inhi- bition 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 sec- ondary recrystallized Fe83Gal7 ＋ 0.5 at% NbC and Fes3Gaw ＋ 0.2 at% B alloy sheets, respectively.展开更多
基金supported by the Major State Basic Research Development Program of China(No. 2011CB606304)the National Natural Science Foundation of China(No.51271019)the Fundamental Research Funds for Central Universities of China(FRF-SD-12-025A)
文摘The〈100〉oriented Fe83Ga17 alloy rods with various NbC contents less than 1at%were prepared by the directional solidification method at a growth rate of 720 mm·h^-1. Low NbC-content was found to affect the oriented grain growth and slightly improve the〈100〉ori-entation. Flat grain boundaries in the alloys with low NbC contents less than 0.2at%became greatly curved at higher NbC contents, and a large amount of Nb-rich precipitates were observed in the alloys with high NbC contents. Small amounts of NbC, less than 0.2at%, resulted in an increase in magnetostrictive strain due to the improvement of the〈100〉orientation, and a high magnetostrictive strain value of 335 ×10^-6 under a pre-stress of 15 MPa was obtained in the 0.1at%NbC-doped alloys. The magnetostrictive performance obviously decreased with the NbC addition higher than 0.5at%, and the strain sensitivity under no pre-stress was lower than that in the binary Fe？Ga alloy.
基金financially supported by the National Natural Science Foundation of China(Nos.51501006 and 51271019)
文摘Inhibition force of precipitate particles for pro- moting abnormal grain growth in magnetostrictive Feg3Ga17-（B,NbC） alloy sheets was investigated in this study. After a continuous heating and a high-temperature annealing, the Fe83Gat7 ＋ 0.5 at% B alloy sheets do not occur significant abnormal grain growth. Correspondingly, textures of { 111 }〈112〉 and { 100}〈00l〉 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 Fe83Gaj7 ＋ 0.5 at% NbC alloy sheets due to the abnormal grain growth, which results in a sharp Goss texture. BN precipitates were introduced into Fes3Ga17 ＋ 0.2 at% B alloy sheets by nitriding annealing at 800℃ 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 decom- pose at high temperature due to the low thermal stability, resulting in a decrease or even disappearance of the inhi- bition 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 sec- ondary recrystallized Fe83Gal7 ＋ 0.5 at% NbC and Fes3Gaw ＋ 0.2 at% B alloy sheets, respectively.
