Effects of Ambient Temperature and Magnetic Field on Damping Capacity of Fe-13Cr-2.5Mo Damping Alloy

The damping capacity of Fe-13Cr-2.5Mo alloy at varying ambient temperatures and alternate-current magnetic field were measured with improved reversal torsion machine. The microstructure was observed with scanning electronic microscope. The results showed that the damping value resulted from both ferromagnetic and un-ferromagnetic parts. The former contributed to about 80%~90% and the latter 10%~20% at 23℃. As the ambient temperature increased from 23℃ to 550℃, the damping capacity decreased slowly to 60%~70% of that at 23℃ finally. Compared with the specimen water-cooled at 900℃, the damping-maximum torsion strain of the furnace-cooled at 1100℃ was much lower, which meaned that its damping reaction to the environmental noise was more intensive. The grain size, carbide precipitation and microscopic residual stress were the main reason that the damping-maximum torsion strain amplitude was higher when the alloy was heated at 900℃ for 2h and water-cooled.