Evolution of microstructure and texture in directionally solidified magnetostrictive Tb_(0.3)Dy_(0.7)Fe(1.95-x)Ti_x [x = 0,0.025,0.05 and 0.075] alloys

摘要

A brief description on the microstructure, texture and magnetostrictive properties of Tb_(0.3)Dy_(0.7)Fe(1.95-x)Ti_x [x=0, 0.025, 0.05 and 0.075], conventionally cast and directionally solidified at 70cm/h by adopting modified Bridgman technique is presented in this paper. The directionally solidified samples show prevalence of strong (110) and (112) texture components at low concentration (x = 0.025) of Ti and at higher concentrations (x>= 0.025), mixed texture components of (110), (112), (11 3), (331) and (531). The microstructure of the Ti containing alloys indicates the absence of deleterious (Tb,Dy)Fe_3 and presence of another Laves phase TiFe_2. The magnetostriction values increase for low concentration of Ti and with further addition it decreases. The decrease in magnetostriction is attributed to the presence of mixed texture components and TiFe_2 in the microstructure.