Composition dependence of thermal stability and crystallization behavior of Ni₂₄(ZrM)₇₆ amorphous alloys

Amorphous Ni_0.24(Zr_1-xM_x)_0.76 alloys with M = Si or P and with 0.0 ≤ × ≤ 0.1 have been prepared by the melt-spinning technique. Crystallization behavior of these alloys has been studied by differential scanning calorimetry, transmission electron microscopy and X-ray diffraction. These amorphous alloys exhibit eutectic crystallization. With increasing silicon or phosphorus content, the crystallization temperature and the microhardness were found to increase monotonically but in a non-linear fashion. On the other hand, the activation energy for crystallization was found to be very sensitive to composition. The ternary alloys containing silicon transformed directly to equilibrium phases upon crystallization, but some of the ternary alloys with phosphorus crystallized through the formation of a transient phase. The thermal properties and the crystallization process of these alloys are discussed.