Crystallization of Fe, Co and Ni based metallic glasses

Abstract

The crystallization of spin quenched metallic glasses (FeNiCo) 0.75P 0.16B 0.06 Al 0.03 has been investigated in the region near the glass transition temperature using differential scanning calorimetry. The effect of the semimetallic component on crystallization was also studied in the Fe and Co based glasses. Some glasses in the CoNi system showed two crystallization peaks and were unstable ( T x ⩽ T g). The FeCo based glasses were least stable for Fe and Co rich compositions; the most stable glasses in this system were near x = 0.5. Apparent activation energies of crystallization Δ E, were observed to show a close correlation to the relative stability of these glasses. Δ E ranged <70 kcal/mole for more CoNi glasses. The less stable glasses showed a lower Δ E. This behavior is discussed in terms of structure relaxation.