Time-resolved X-ray diffraction study of the transition of an amorphous TiCu alloy to the crystalline state

Resumo

The transition of the TiCu alloy from an amorphous state to the crystalline state has been studied by time-resolved X-ray diffraction. An analysis of the diffraction pattern has shown that the crystallization of the amorphous TiCu alloy upon heating occurs for a short time (no longer than 0.5 s). A sharp transition is observed at the instant of crystallization, at which the intensity of the total diffraction pattern background decreases and diffraction lines of the crystalline phase γ-TiCu arise. No intermediate crystalline phases are observed. The change in the alloy structure is accompanied by the exothermic thermal effect. The kinetics of the change in the total intensity of the diffraction spectrum in the period preceding the crystallization is nonmonotonic. Ten seconds before the occurrence of diffraction lines of the γ-TiCu phase at 300°C, the integrated spectral intensity decreases. The effect observed is related to the relaxation processes in the amorphous state and the onset of formation of long-range structural order.