Mechanical property and damping capacity of ultrafine-grained Fe-13Cr-2Al-1Si alloy produced by equal channel angular pressing

Mechanical property and damping capacity of ultrafine-grained (UFG) Fe-13Cr-2Al-1Si ferromagnetic alloy were studied using tensile testing, Vicker's hardness testing and internal friction measurement (IF). Equal channel angular pressing (ECAP) method was employed to refine the grain size of the material to UFG level. The tensile strength and microhardness of UFG samples are evidently improved after the refinement of grain size. The damping capacity of UFG samples is somewhat lower than that of the coarsen-grained samples due to the pinning effect of the introduced crystal defects (i.e. dislocations and sub-grain boundaries etc) on the movement of magnetic domain walls. A high nonrelaxation IF peak is observed at about 650 °C in the heating run which should be related to recovery of the dislocation and recrystallization of UFG alloy. There are two relaxation IF peaks in the cooling run: one is Zener peak at the range of 550∼600°C and another is grain boundary peak at the range of 660∼720°C.