Thermal embrittlement of Fe-based amorphous ribbons

Thermal embrittlement of amorphous Fe78−xNixSi10B12 and Co78Si10B12 alloys has been studied. The majority of Fe-based amorphous alloys became brittle after annealing to temperatures significantly lower than their crystallization temperatures, whereas the non-Fe-based amorphous alloys remained ductile after annealing up to their crystallization temperatures. The present results emphasize on the key difference between the embrittlement behavior of Fe-based and non-Fe-based amorphous alloys. We point out a possible correlation between different phenomena like Invar effect, compositional inhomogenity, and residual stress playing a critical role in the thermal embrittlement of Fe-based amorphous alloys.