Effect of Annealing Temperature on Damping Capacity and Magnetic Domain Structure of Fe-7Al-0.5Ti Alloy

The damping capacity of Fe-7Al-0.5Ti alloy annealed at different temperature was measured by reversal torsion apparatus.The water-based magnetic fluid was used to analyze the variation of magnetic domain structure.The precipitation along the grain boundary was investigated by SEM.The results show that there exists a damping peak when the alloy is annealed at 1000℃ for 2h and water-cooled.The internal stress and defects decrease with the increase of heat treatment temperature and this makes magnetic domains wider and more orderly,but the carbides containing Ti precipitate along the grain boundaries which cause local components and structure heterogeneousness in these areas.As a result,the magnetic domains are narrower,the domain boundary motion is obstructed,and the improvement of damping capacity of this alloy is also affected.