TY - JOUR
T1 - Diffusion of iron in Mg60Ni25Nd15 amorphous alloys with a wide supercooled liquid region
AU - Nakajima, H.
AU - Honma, Y.
AU - Nonaka, K.
AU - Shiozawa, K.
AU - Nishiyama, N.
AU - Inoue, A.
AU - Masumoto, T.
PY - 1994/5/1
Y1 - 1994/5/1
N2 - Impurity diffusion of 59Fe in Mg60Ni25Nd15 amorphous alloys with a wide supercooled liquid region has been investigated over the temperature range from 407 to 469 K. Concentration depth profiles of the radioisotope 59Fe in Mg60Ni25Nd15 supercooled liquid and amorphous alloy have been measured by an ion beam sputter-sectioning technique. The temperature dependence of the impurity diffusivity of Fe in Mg60Ni25Nd15 supercooled liquid (446-469 K) and amorphous alloy (407-438 K) is expressed as respectively D(supercooled) = 2.0 × 10-10 exp (-53.3 ± 3.5 kJ mol-1/RT)m2s-1 and D(amorphous) = 7.7 × 103 exp (-164.0 ± 19.4 kJ mol-1/RT) m2 s-1 The temperature dependence of Fe diffusivities in the supercooled liquid region is less significant than that in the amorphous phase; the activation energy for diffusion in the supercooled liquid region is much smaller than that in the amorphous alloy by a factor of 3. Such a temperature dependence is consistent with results of viscosity measurement.
AB - Impurity diffusion of 59Fe in Mg60Ni25Nd15 amorphous alloys with a wide supercooled liquid region has been investigated over the temperature range from 407 to 469 K. Concentration depth profiles of the radioisotope 59Fe in Mg60Ni25Nd15 supercooled liquid and amorphous alloy have been measured by an ion beam sputter-sectioning technique. The temperature dependence of the impurity diffusivity of Fe in Mg60Ni25Nd15 supercooled liquid (446-469 K) and amorphous alloy (407-438 K) is expressed as respectively D(supercooled) = 2.0 × 10-10 exp (-53.3 ± 3.5 kJ mol-1/RT)m2s-1 and D(amorphous) = 7.7 × 103 exp (-164.0 ± 19.4 kJ mol-1/RT) m2 s-1 The temperature dependence of Fe diffusivities in the supercooled liquid region is less significant than that in the amorphous phase; the activation energy for diffusion in the supercooled liquid region is much smaller than that in the amorphous alloy by a factor of 3. Such a temperature dependence is consistent with results of viscosity measurement.
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U2 - 10.1016/0921-5093(94)90221-6
DO - 10.1016/0921-5093(94)90221-6
M3 - Article
AN - SCOPUS:0028426420
VL - 179-180
SP - 334
EP - 336
JO - Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing
JF - Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing
SN - 0921-5093
IS - PART 1
ER -