Study On Recrystallization Texture And Magnetic Properties In Fe₈₁Ga₁₉ Thin Sheets

Fe-Ga alloys have great potential as advanced engineering materials for actuator and sensor applications in terms of the superior comprehensive properties,such as large magnetostriction at very low saturation field,combined strength and ductility,weak temperature sensitivity,negligible magnetic hysteresis and relatively low cost.The excellent magnetostriction and mechanical properties are likely to significantly expand the design space for the use of Fe-Ga alloys in the field of smart structures.Fe-Ga alloy exhibits the largest magnetostriction coefficient along<100>direction,it is desirable to produce rl(<100>//RD)textured Fe-Ga polycrystalline thin sheet with excellent magnetostrictive performance.Though the strong η textures have been achieved by secondary recrystallization,but overlarge grains can deteriorate mechanical properties.Consequently,how to optimize texture in fine grained microstructure is an important problem for excellent comprehensive properties.In the present study,strong η texture and fine grained microstructure of Fe81Ga19 thin sheet was successfully produced by rolling and annealing.Furthermore,texture development was analyzed by X-ray diffraction(XRD)and electron backscattered diffraction(EBSD),as well as magnetostriction and tensile properties are analyzed.(1)Strong η recrystallization texture and fine grained microstructure in 0.5mm thick Fe-Ga sheets by suitable cold-rolling reduction(70%)and annealing temperature(800℃～900℃),and excellent magnetic and mechanical properties is achieved.(2)Strong η recrystallization texture is propitious to dominating magnetostriction.The enhancement of η texture attributes to η grain have the size advantage form preferentially nucleated in shear bands and growing without strong obstacle.But the preferential growth ofη grain lead to the heterogeneous distribution of grain size,go against mechanical properties.(3)Control of stored energy of shear band and grain boundary regions as well as thickness of deformed grain can achieve optimization of η grain size by adopted appropriately initial condition and cold rolling parameters.(4)The work systematically studies the grain size and texture evolution of Fe-Ga alloy under the influence of cold rolling reduction,which can provide an important reference for the preparation of Fe-Ga alloy with different requirements.