The study of eutectoid decomposition kinetics of Cu50Zr50 alloy

The process of the eutectoid decomposition CuZr → Cu10Zr7 + CuZr2 in a Cu50Zr50 alloy under isothermal and non-isothermal conditions was investigated by using differential scanning calorimetry, electrical resistivity, X-ray diffraction, optical microscopy and dilatometer techniques. The continuous cooling transformation and time–temperature transformation diagrams for the decomposition of CuZr were determined over a wide temperature range. It was observed that the decomposition process is extremely slow in comparison with many other copper-based systems. The kinetics of the eutectoid decomposition under isothermal conditions was discussed within the frameworks of the Johnson–Mehl–Avrami theory. Kinetics parameters of eutectoid decomposition, namely the activation energy Ea = 395 ± 24 kJ mol−1 and the power n = 3.3 ± 0.1 in Avrami exponent, were determined.