TEM study on oxidized TiCrN coatings ion-plated on a steel substrate

• Published in: Surface & coatings technology Vol. 173; no. 1; pp. 81 - 86
• Main Author: Lee, D.B.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01.08.2003; Elsevier
• Subjects: Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Ion plating; Mechanical and acoustical properties; Oxidation; Physical properties of thin films, nonelectronic; Physics; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); TiCrN coating; TiCrN coating; Ion plating; Oxidation; Thin films; Chromium nitrides; Transmission electron microscopy; Ternary compounds; Surface treatments; Experimental study; Microstructure; Coatings; Titanium nitrides
• ISSN: 0257-8972; 1879-3347
• DOI: 10.1016/S0257-8972(03)00519-X

Coatings of TiCrN having compositions of (TiCr 0.7)N, (TiCr 1.2)N and (TiCr 3.6)N were ion-plated on a steel substrate. The coatings were oxidized at 800 °C for 50 h in air, and the resultant morphology and compositional variance were studied utilizing transmission electron microscopy. The scales consisted of fine TiO 2 and Cr 2O 3 grains, of which forming-tendency, size and the location in the oxide scale strongly depended on the Ti/Cr ratio of the coatings. During oxidation, not only the coating elements (Ti and Cr) but also the substrate element (iron) predominantly diffused outwards. At the same time, inward diffusion of oxygen from the atmosphere occurred. A detailed oxidation mechanism of TiCrN coatings is presented.