High temperature X-ray diffraction studies on the crystallization of amorphous Fe-Zr-B alloys

Crystallization behaviour of amorphous Fe-Zr-B alloys was investigated by means of high temperature X-ray diffraction measurements. The diffraction patterns were recorded isothermally and during heating at a rate of T = 20 K/min from room temperature to 800 degrees C at measuring intervals of 10 degrees C each. The in situ observation of the crystallization enables the direct observation of structure evolution of as a function of heat treatment. The phases formed and the phase sequence can be determined and compared with the corresponding DSC signal. In the first stage of crystallization b.c.c. iron is formed primarily. In the second stage intermetallic Fe-Zr phases are found. From time and temperature resolved measurements phase transformation diagrams were extracted. The crystallization process of amorphous Fe-Zr B alloys is characterized by the formation of a temperature dependent number of nuclei growing to nanosize.