Effect of overheating treatment on microstructure and crystal orientation of TbDyFe alloy

Abstract

TbDyFe is a kind of magnetostrictive material with good magnetostrictive properties, especially in <111> direction. The effect of overheating treatment on the microstructure and crystal orientation of Tb_0·27Dy_0·73Fe_1·9 alloy was investigated. The results show that overheating treatment has considerable effect on the process of solidification, microstructure and crystal orientations. Under the condition of single overheating, the grain size decreased and the crystal orientation changed from <113> to <125> direction with the increase in overheating temperature. Under four times overheating treatment, the microstructure initially became coarser with the overheating temperature, then turned to become finer, and crystal orientations compete each other when overheating temperature is ∼200°C. Under eight overheating treatments, the microstructure was kept almost the same at different overheating temperatures, and <110> and <113> oriented grains were in the majority when overheating temperature was ∼200°C.