Zirconium phase transformations observed by “in-situ” XRD analysis

The high temperature phase transformations of zirconium were investigated by “in-situ” X-ray diffraction analysis. The experiments were carried out in a high temperature chamber Anton Paar HTK 1200N mounted on powder diffractometer Panalytical X’Pert Pro. The chamber was evacuated by a turbo-molecular pump creating a pressure about 3 × 10−4 Pa at the temperature 1200 °C before the measurement. The experimental samples were uniformly heated without thermal gradients up to 1000 °C or 1200 °C and then exposed for 180 min. At high temperature four or six diffraction patterns of each sample were recorded for the illustration of the phase changes in the material structure. Chemical composition of some samples after the exposure was determined by secondary ion mass spectrometry and compared with composition of the material in its initial state.

► We studied phase transformations of pure Zr at high temperatures by “in situ” XRD.
► Four experimental samples were exposed in evacuated high temperature chamber.
► The transformation temperature is strongly influenced by free nitrogen and oxygen.
► The high temperature beta phase of Zr could be observed even at 1200 °C.
► The theoretical value of pure Zr transformation temperature is 860 °C.