HIGH-TEMPERATURE CREEP OF NANOCRYSTALLINE FE-B-SI ALLOY

Tensile creep of nano-grained (27 nm) and coarse-grained (250 nm) samp les of Fe78B13Si9 alloy has been studied at temperatures around 0.5 T- m (T-m is the melting point). The strain-time relations in the primary Creep of both grained samples are found to obey the Andrade's exponen tial law. The stress exponents and activation energies measured in the steady state creep indicate that the creep of the nano-grained sample s is controlled by grain (and/or phase) boundary diffusion, while the creep of coarse-grained samples is controlled by a combined mechanism. The creep of the Fe-B-Si alloy exhibits the same feature as that of N i-P alloy reported in our previous work.