Research Of Crystallographic Textures And Magnetic Property In Rolled And Recrystallized Fe-Ga Sheet

Fe-Ga alloy has received wide spread attention in recent years as a new magnetostrictive materials with low saturation magnetization field, good mechanical properties and temperature characteristics. It has the significant magnetic anisotropy with the largest magnetostriction coefficient along<100> direction. The method of preparing Fe-Ga alloy mainly includes single crystal growth or unidirectional solidification, both of which are expensive and inefficient.Moreover,high electrical conductivity results in a serious high-frequency eddy current loss, so it’s necessary to cut into thin slices. Therefore, the conventional rolling method can realize the sheet forming and produce ideal η (<100>//RD) texture to optimize the magnetostriction performance.In this study, Fe-Ga alloy sheet of good texture feature was prepared through conventional rolling procedure which consisted of hot rolling, normalizing, cold rolling and recrystallization annealing. Based on solving the rolling formability, the research was focused on the effect of the initial grain size after normalizing and the cold rolling reduction on primary and secondary recrystallization textures. This paper establishes an important foundation for the development of high grade Fe-Ga alloy sheet.Primary recrystallization texture mainly consists of Goss ({110}<001>) and γ fiber texture changed from cold rolling texture dominated by y fiber (<111>//ND) and a fiber (<111>//ND) texture. Initial grain sizes after normalizing and cold rolling reductions has a great influence on primary recrystallization microstructure and texture. The analysis of primary recrystallization texture shows that the decrease of grain size after normalizing and cold rolling reduction of 70% is favor of obtaining more Goss texture component during primary recrystallization annealing.We make a study about the evolution of η texture through second recrystallization annealing,especially the the effect of the initial grain size after normalizing and the cold rolling reduction on the microstructure and texture during second recrystallization. The result of this research indicates that decrease of grain size after normalizing and cold rolling reduction of 70% promote the second recrystallization to obtain stronger η texture. On the other hand, saturated magnetostrictive of specimens by this route can reach up to 170ppm.Thus, the present results provide a prospective route to efficiently optimize the primary and second recrystallization texture of Fe-Ga alloy through reasonable rolling process flow and the annealing process.