Temperature Dependence of Self-Diffusivities in B~2-Type intermetallic Compornds

摘要

Temperature dependence of the self-diffusivities in B_2type intermetallic compounds has been investigated. The self-diffusivities plotted against the inverst of temperature normalized by the solidus temperatures, T_f, show that the activation energy,Q,isrelated to T_fby Q=(19±8)RT_f~B2 j/mol, and the pre-exponential factor, D_o is in a certain range, D_o=10~∽10~-6m~2s~-2. How-ever, the results of CuZn, which have the order-disorder transformation below solidrs temperature, are out of range of a large numberof data. The hypothetical T_0~B2/T shows a tendency similar to that of other B2-type intermetallic compounds. The relationship between the activation energy of self-diffusion and the enthalpy of fusion of the ordered phase is also discussed.