The influence of the O2/C2H2 ratio on the structure and properties of Fe66Cr10Nb5B19 detonation coatings

• Published in: Materials today : proceedings 2020, Vol.25, p.384-386
• Main Authors: Kuchumova, Ivanna D., Batraev, Igor S., Cherkasova, Nina Y., Rybin, Denis K., Ukhina, Arina V., José Botta, Walter, Yuuki Koga, Guilherme, Moreira Jorge, Alberto
• Format: Article
• Language: English
• Subjects: Acetylene; Detonation spraying; Explosive charge; Microstructure; Oxide films; Oxygen; Ratio
• ISSN: 2214-7853; 2214-7853
• DOI: 10.1016/j.matpr.2019.12.098

The temperature and dynamic pressure of the detonation products are parameters that determine the heating and acceleration of particles during the detonation spraying. These parameters depend on the composition of the explosive mixture. The present article reports the influence of the composition of the acetylene–oxygen explosive mixture on the structure and properties of detonation coatings obtained from a multi-component Fe-based alloy. A gas-atomized powder with a nominal composition of Fe66Cr10Nb5B19 was used for depositing the coatings. The O2/C2H2 molar ratio was 1.1; 1.5 or 2.0; the volume of the explosive mixture was constant. At an O2/C2H2 ratio of 1.1, the coating was 99% amorphous. As the O2/C2H2 ratio was increased, the content of the crystalline phase in the coatings increased. At higher oxygen contents, oxidation of the particle surfaces during spraying is more likely. Possibly, oxide films formed in-situ may act as heterogeneous nucleation sites for crystallization, which leads to a decrease in the content of the amorphous phase in the coatings. The increase in the O2/C2H2 ratio from 1.1 to 2.0 also leads to increased porosity and decreased coating microhardness.