In Situ Neutron Diffraction Study of Ni Addition in Co–Re–Cr High-Temperature Alloys and Influence on Phase Transformations

The influence of Ni addition to the phase transformation in the Co–17Re–23Cr high-temperature alloy was studied using neutron diffraction techniques. Three different alloys with 8, 15 and 25% of Ni were analyzed. The Ni effect on stabilization of cubic phase of Co matrix was confirmed, and the influence on σ-phase was reported. Formation of the secondary cubic phase with the smaller cell during heating and cooling associated with the creation of Re-rich σ-phase was observed. The summary phase diagrams for heating and cooling are created to depict the overall Ni influence on Co–17Re–23Cr alloy.