Formation of CrxCyOz Coatings under Laser Treatment of Chromium Carbide Ceramics

• Published in: Inorganic materials : applied research 2020, Vol.11 (3), p.610-618
• Main Authors: Fironov, Ya. S., Vlasova, M. V., Melnikov, I. V., Kakazey, M. G., Reséndiz-González, M. C., Kondrashenko, S. I., Ryabtsev, D. A.
• Format: Article
• Language: English
• Subjects: Ablation; Additives; Ceramic coatings; Ceramics; Chemistry; Chemistry and Materials Science; Chromium carbide; Clusters; Coagulation; Craters; Functional Coatings and Surface Treatment; Industrial Chemistry/Chemical Engineering; Inorganic Chemistry; Lasers; Materials Science; Morphology; Nanoparticles; Oxidation; Oxycarbides; Pulsed lasers; Vapor phases
• ISSN: 2075-1133; 2075-115X
• DOI: 10.1134/S2075113320030132

The effect of the pulsed laser irradiation in air on Cr 23 C 6 ceramic with Cr 3 C 2 and Cr 7 C 3 additives has been studied. It is established that the main process occurring in the zone of laser radiation is the melting of the ceramic surface of chromium carbide and the formation of a crater. This process is accompanied by the ejection of melt droplets from the crater zone and the dissociation of chromium carbides. As a result, the crater area is enriched in such ablation products as Cr, C, CO, and CO 2 . Reduction of hydrogen in the crater zone and neighboring areas leads to slowing down of the rate of oxidation processes, and the presence of ablation products such as Cr and C atoms promotes the process of synthesis of oxycarbides Cr x C y O z ( x ≈ 0.3–0.8, y ≈ 0.03–0.3, z ≈ 0.61–0.26) in the gas phase. Emission of the newly formed products of ablation from the crater and their distribution to the neighboring areas is accompanied by coagulation of nanoparticles into clusters. Depending on the length of flight of nanoclusters through different temperature zones and temperature of the deposition surface, oxycarbides with different morphology are formed: from islets (like fractal clusters) to film ones. The deposited ablation products are characterized by the signs of particle size “separation.” This makes it possible to create films of a given type and purpose. The passage of particles of different sizes through a gaseous medium containing oxygen is accompanied by the oxidation of oxycarbides to Cr 2 O 3 .