Phase Composition of Heat-Resistant Layered Coatings of the Al–Cr–Ni System

Abstract

The results are provided for a study of the effect of high-temperature action duration in an air atmosphere at 1150°C for 100, 200, and 300 h on phase and chemical composition of heat-resistant layered coatings of the Al–Cr–Ni system. A collection of methods of electron microscopy (Z-contrast regime), energy-dispersion, and x-ray phase analyses shows that the main structural component of a diffusion barrier, providing a stable composition for a (NiAl + Ni₃Al) coating and its heat resistance, are chromium-based solid solutions with a content in the range 93–99 at.%, and also solid solutions based on phases Ni₃Cr, Ni₃Cr₂, and Ni₃Al.