| The damping behavior of ferromagnetic Fe-Al-Mn alloy was investigated. The effect of aluminium content and heat treatment on the specific damping capacity(SDC) of alloys was studied over a range of Al 3-13wt.%. After heated at 1000℃ for 40 minutes in a vacuum furnace, alloys were cooled by three different ways; furnace cooling, air cooling and water quenching. By the results of X-ray and neutron diffraction test, the relations between the crystal structure and the magnetic structure were clarified. The average domain size by neutron diffraction showed the minimum value of 10.5㎛ at 5.5% Al content. SDC results showed that SDC_(max) reached its highest value of 35% at a range of 5-6wt.%Al. On the basis of the data obtained by analyzing magnetic hysteresis loops and neutron scattering method, it was found that alloys subjected to furanace cooling and air cooling had higher SDC_(max) than that of water quenched one, because they had more volume of 90˚ magnetic domain. Compared with the furnace cooled alloy, the air cooled one showed higher SDC_(max) value, because it had not short range order. |
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