Thermodynamic Study of Liquid Ni–Cr Alloys Equilibrated with Cr₂O₃ by EMF Method

Abstract

Oxygen solubility and chromium activity in Ni–Cr alloys equilibrated with Cr₂O₃ were measured by a conventional sampling method and the emf method with stabilized zirconia in the concentration range from 2 to 70 at%Cr at the temperatures of 1733 to 1833 K. Temperature dependences of oxygen solubility are as follows:
log(10²N_O)=(−12130±2750)⁄T⁄K+(4.860±1.538) for X_Cr=0.02,
(−12760±890)⁄T⁄K+(5.386±0.498) for X_Cr=0.10,
(−10790±1390)⁄T⁄K+(4.682±0.777) for X_Cr=0.20,
(−11160±1300)⁄T⁄K+(5.300±0.734) for X_Cr=0.30,
(−9660±230)⁄T⁄K+(4.751±0.126) for X_Cr=0.40,
(−9700±920)⁄T⁄K+(5.001±0.510) for X_Cr=0.50.
Activities of Cr show negative deviations from Raoult’s law in the nickel rich region and negative to positive deviations in the middle concentration region at 1783 K. The results were compared with the literature data.