Formation of the diffusion barrier at the interface of Cr20Ni80 alloy - Ni-Cr-Al coating

[摘要] The effect of thermal influence conditions on the structure and chemical composition of the self-organizing diffusion barrier formed during higherature (1100 °C) long-term (up to 500 h) heating between the Cr20Ni80 alloy and the coating of the Ni-Cr-Al system is investigated. It is shown that the formation of a barrier, which is a Cr(Al) solid solution of variable composition, is due to the limited solubility of Cr in Ni aluminides. It is established that the growth of the thickness of the diffusion barrier is mainly due to the alloy Cr20Ni80, and the intensity of its growth and the content of chromium in it are determined by the temperature and time conditions of heating. With a diffusion barrier thickness of 55-60 μm, its further growth is stopped by blocking the diffusion flux of Ni from the alloy Cr20Ni80 into the coating.

[发布机构] Department of Materials Science and Composite Materials, Volgograd State Technical University, 28 Lenin Avenue, Volgograd; 400005, Russia^1

[效力级别] 工业技术

[关键词] Al coatings;Chemical compositions;Diffusion fluxes;Ni aluminides;Thermal influence;Time condition