Research On Microstructure And Properties Of Secondary Recrystallization Of Two-stage Cold Rolling Fe₈₁Ga₁₉ Sheet

In recent years,Fe-Ga alloy has attracted more and more attentions attribute to its excellent characteristics,such as high strength,good toughness,high magnetostriction at low magnetic fields,and low cost.In order to reduce the eddy current loss generated at high frequency,Fe-Ga alloy is needed to be processed into thin sheet.The key problem of thin Fe-Ga alloy sheet is the enhancement of ? texture by secondary recrystallization,and the main method to improve magnetostriction is to obtain secondary recrystallization Goss texture by adding inhibitors.In present study,the thin Fe-Ga alloy sheet with a compounded inhibitor of intrinsic Cu2S and obtained inhibitor of AlN were manufactured through low reheating temperature and two-stage cold rolling technique.The evolution of microstructure and texture during rolling and annealing process were studied.The influence of rapid annealing and nitriding process on secondary recrystallization microstructure and magnetic property were researched at the same time.Main creative points and conclusions as follows:(1)Thin annealed sheets with primary recrystallization texture dominated by Goss texture are obtained when the secondary cold rolling reduction is 55%?65%.The strong Goss primary recrystallization texture is attributed to the n?mber and size superiority provided by the appropriate deformation microstructure.(2)Secondary recrystallization of Goss grain is successfully achieved by rapid annealing and Cu2S+AlN inhibitors.And the microstructure and property of Fe-Ga alloy are optimized by controlling the parameter of rapid annealing process.The result indicates that the grain size of secondary recrystallization and magnetostriction decreased as the secondary cold rolling reduction increased,which should be attributed to the difference of primary recrystallization microstructure and texture.(3)The secondary recrystallization of Fe-Ga alloy sheet is promoted by the optimization of nitriding process.The overall inhibition effect increased with the nitriding time,which inhibit the growth of the matrix grain during rapid annealing.Thus,the n?mber and distribution of inhibitors and annealing temperature during secondary recrystallization should be controlled,in order to ensure the significant growth driving advantage and growing space of Goss grain compared with that of matrix.(4)The method of preparing thin Fe-Ga alloy sheet with higher magnetostriction by rapid annealing is proposed.The rolling and annealing process should be controlled to obtain more accurate primary recrystallization gains.The inhibitor system and nitriding process are optimized to ensure the rapid abnormal growth of Goss grains and the sufficient inhibition of matrix.