Decomposition Kinetics of Ferromagnetic Phase in Mn - Al - C Magnetic Alloy
소찬영Chan Young So, 이동희Dong Hi Lee
Abstract
A kinetic investigation was carried out on the decomposition of ferromagnetic τphase in Mn-Al-C alloys of three different carbon contents (O, 0.18 and 0.27wt.% at a fixed Mn of 70.wt.%) by means of the isothermal heat-treatment at temperatures ranging 600∼700℃. The results obtained can be summarized as follows; 1) The decomposition of τphase to β-Mn and γphases was analysed to follow the nucleation and growth mechanism. Nucleation took place at the phase boundaries to form β-Mn first, and then γphase subsequently. 2) The decomposition of τphase was inhibited by carbon addition and showed the stabilization effect of τphase in Mn-Al-C alloys. The activation energy calculated for the decomposition was ranged 64.1㎉/mole for Mn-Al alloys to 70.6 and 75.3㎉/mole for Mn-Al-C alloys.