Detonation-Sprayed Coatings of (Ti, Cr)B2–NiAlCr Composite Materials II. Mechanical and Tribotechnical Properties
Powder Metallurgy and Metal Ceramics 2020
V. P. Konoval, Armands Leitāns, Irīna Boiko, О. P. Umanskyi, V. Yu Chernatska, V.I. Subbotin

The mechanical and tribotechnical properties of detonation-sprayed coatings produced from (Ti, Cr)B2–NiAlCr composites were studied. The influence of various preliminary substrate treatment methods and refractory-to-metal ratio in the spray material on the coating–substrate adhesion strength, σad, was analyzed. Spraying a sublayer had no significant effect on the coating adhesion strength. The adhesion strength σad increased by 25–30% with the metal content changing from 25 to 75%, while σad = 120–145 MPa even at 25% NiAlCr. The hardness of the coatings changed within rather narrow limits (HV0.2 = 7–12 GPa), but the refractory-to-metal ratio varied over a wide range. The coatings containing a minimum amount of the metal component (25%) were predicted to have higher hardness, HV0.2 = 10–12 GPa, though it was almost half the hardness of the sintered compact material. At equal contents of the refractory and metal components, HV0.2 = 9–10 GPa; for the material containing 75% of the metal component, HV0.2 = 7–8 GPa. The tribotechnical properties of the coatings were studied in dry sliding friction conditions with ball-ondisk tests. At the initial friction stage, high pressures appeared in the contact zone (P ≥ 500 MPa). Therefore, in addition to high hardness, the coatings should have high strength. At 50–75% (Ti, Cr)B2, besides abrasion processes, brittle fracture and spalling of the coatings occurred. The best characteristics were shown by the coating produced from the material containing 25% (Ti, Cr)B2. Since the (Ti, Cr)B2 particles are fine, wetted well by the NiAlCr alloy, and uniformly distributed over the starting material and associated coating, even their relatively low content (25%) promotes high abrasion resistance and adhesion.


DOI
10.1007/s11106-020-00175-0
Hipersaite
https://link.springer.com/article/10.1007/s11106-020-00175-0

Konoval, V., Leitāns, A., Boiko, I., Umanskyi, О., Chernatska, V., Subbotin, V. Detonation-Sprayed Coatings of (Ti, Cr)B2–NiAlCr Composite Materials II. Mechanical and Tribotechnical Properties. Powder Metallurgy and Metal Ceramics, 2020, Vol. 59, No. 7-8, 411.-423.lpp. ISSN 1068-1302. e-ISSN 1573-9066. Pieejams: doi:10.1007/s11106-020-00175-0

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English (en)
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