• Korean Journal of Materials Research
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• v.26 no.12
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• pp.688-695
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• 2016

Recrystallization behavior has been investigated for commercial purity AA1050 (99.5wt%Al) and high purity 3N Al (99.9wt% Al). Samples were cold rolled with 90% of thickness reduction and were annealed isothermally at 290, 315, and 350o C for various times until complete recrystallization was achieved. Hardness measurement and Electron Backscatter Diffraction(EBSD) analyses, combined with Grain Orientation Spread(GOS), were employed to investigate the recrystallization behavior. EBSD analysis combined with GOS were distinctly revealed to be a more useful method to determine the recrystallization fraction and to characterize the recrystallization kinetics. As the annealing temperature increased, recrystallization in AA1050 accelerated more than that process did in Al 3N. Both AA1050 and Al 3N showed the same temperature dependence of the n value of the Johnson-Mehl-Avrami-Kolmogorov equation(JMAK equation), i.e., n values increased as annealing temperature increased. Activation energy of recrystallization in AA1050 is about 176 kJ/mol, which is comparable with the activation energy of grain boundary migration in cold-rolled AA1050. This value is somewhat higher than the activation energy of recrystallization in Al 3N.

• Korean Journal of Materials Research
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• v.8 no.11
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• pp.1026-1030
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• 1998

Thermal properties of Fe- base amorpous alloys were investigated. $Fe_{80}P_6C_{12}B_{12}$ and $Fe_{73}P_{11}C_6B_4AI_4Ge_2$ amorphous alloys were fabricated by melt spinning method and thermal analysis was done by differential scanning calorimeter. After isothermal crystallization. the Avrami exponents of $Fe_{80}P_6C_{12}B_{12}$ and $Fe_{73}P_{11}C_6B_4AI_4Ge_2$ amorphous alloys were 1.8-2.2 and 2.5-4.0, respectively. It means the former alloy shows diffusion controlled growth and the latter one shows interface controlled growth. For $Fe_{80}P_6C_{12}B_{12}$ and $Fe_{73}P_{11}C_6B_4AI_4Ge_2$ amorphous alloys. the activation energies of isothermal crystallization was 353 and 371kJlmol. Also the activation energies of nucleation and growth were 301, 324kJlmol and 273. 30lkJ/mol, respectively. Thus $Fe_{73}P_{11}C_6B_4AI_4Ge_2$ amorphous alloy is considered to be more stable than $Fe_{73}P_{11}C_6B_4AI_4Ge_2$ amorphous alloy.