High-temperature interaction of Ce–Fe–As ternary system

Abstract

The high-temperature interaction within a Ce–Fe–As ternary system in a special barrel-shaped cylinder machined by industrial iron was investigated by x-ray diffraction, backscattered electron imaging, and optical microscopy after heated preservation at 1273 K for 50 h. Results showed that the main phases of Ce–Fe–As interaction at high temperature were CeAs, Fe2As, and a small amount of As dissolved in Fe. Increased atomic ratio of Ce to As had minimal effect on the phase change of the sample. Due to iron diffusion, the phase of Fe2As was found near the cylinder-body matrix but not in the center area of the sample. A transition area where Fe, Ce, and As coexisted was observed between the areas whereas Ce–As and Fe–As coexisted. The diffusion of As into the Ce–Fe–As system occurred through the formation of Fe2As, and Ce diffusion occurred through the vacancy mechanism.