DSC analysis of order-disorder transition in Ni3Al based alloys from NI-AL-CR system

Abstract

Ni-Al-Cr system is significant for industrial alloys based on intermetallic phase Ni3Al, that crystallizes in crystal lattice L12. It is indicated as γ', contrary to disordered phase γ which occurs with addition of chromium. DSC analysis was performed on alloys of chemical composition from Ni75Al25-Ni75Cr25 range of Ni-rich part of Ni-Al-Cr system. In addition, few measurements were conducted using DTA method. Based on curves registered, it was possible to identify characteristic temperature during heating and cooling of the sample. It corresponds to existence of phase boundary γ'+γ / γ in examined alloys. Results of thermal analysis were compared with results obtained with other method performed by authors which is solution calorimetric method.