Fe-6.5wt%Si alloy has excellent soft magnetic properties,but it is hard to be cold-rolled due to appearance of ordered phases in this alloy.In this paper we report that ultra thin Fe-6.5wt%Si sheet of 0.05 mm thick was obtained by heavily cold rolling.By means of optical microscope,micro-hardness indenter,instron,SEM and X-ray diffraction,the effect of heat treatment on mechanical properties of this alloy sheet was investigated.The heavily cold-rolled sheet exhibits some extent of ductility.The ultimate tensile strength reaches 1.93 GPa.After heat treatment,micro-hardness is decreased and the ductility is lost,especially at temperature above 650℃ when recrystallization takes place.The reason for decreasing the ductility lies in the ordered DO3 phase transformation.
LIANG YongFeng,YE Feng,LIN JunPin,WANG YanLi,ZHANG LaiQi & CHEN GuoLiang State Key Laboratory for Advanced Metals and Materials,University of Science and Technology Beijing,Beijing 100083,China