PSI - Issue 32

M.A. Eryomina et al. / Procedia Structural Integrity 32 (2021) 284–290 Eremina/ Structural Integrity Procedia 00 (2019) 000 – 000

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It is exciting to compare the properties of a compact and a coating prepared from the same mechanically alloyed powder. Sample 1 shows friction coefficient of 0.45 and 0.33 for friction against a steel disk and a ball made of WC Co alloy, respectively. As for the coating, its friction against a steel ball gives a friction coefficient of 0.2 at the initial stage of testing (5 min) and further increases to 0.28, but paired with a ball made of WC-Co alloy it gives 0.2 with no further changing. Thus, the obtained coatings have lower friction coefficients and reveal practically no wear in the tribo-pair, despite the presence of metallic components (W and bcc Fe) characterized by adhesion and oxidation processes. 4. Conclusion The phase composition, density, microhardness and wear resistance of compacts and coatings based on carbides (Fe,W) 6 C and (Fe,W) 12 C produced by mechanosynthesis in a liquid hydrocarbon with different ratios of tungsten and iron (20-30 wt.% Fe) were investigated. Compacts were obtained by magnetic- pulse compacting at 500°C followed by annealing at 900°C. The compacts shows a microhardness of up to 9.6 GPa and high abrasive wear resistance. The better wear resistance under lubricant-free friction against a steel disc is achieved for minimal proportion of metal (W and bcc Fe), with the coefficient of friction being 0.27 and the wear not exceeding 2  m in the tribopair. For rubbing the compacts against a ball made of WC-Co alloy, the friction coefficient is 0.33-0.53, and the wear not exceeding 10  m in tribopairs. The coatings formed on the surface of iron plates using selective laser sintering contain a higher proportion of tungsten compared to compacts. The microhardness of the coatings is 16 GPa, and the friction coefficients being 0.28 and 0.2 for the friction against balls made of steel and WC-Co alloy, respectively. There is practically no wear in tribopairs. Thus, the combined use of mechanosynthesis and selective laser sintering is an effective way to develop coatings based on η -carbides (Fe,W) 6 C and (Fe,W) 12 C with high hardness and wear resistance. Acknowledgements The authors are grateful to S.V. Zayats (IEP UD RAS) for compacting the samples and V.F. Lys (UdmFRC UB RAS) for conducting tribological tests. The research was carried out with the support of the RFBR (project No. 18-48-180003) and the use of the equipment of the Shared Use Center UdmFRC UB RAS (Gant No. RFMEFI62119X0035). References Matteazzi, P., Le Caer, G., 1991. Room-temperature mechanosynthesis of carbides by grinding of elemental powders. J. Am. Ceram. Soc. 74 (6), 1382 – 1390. Wang, G.M., Campbell, S.J., Calka, A., Kaczmarek, W.A., 1996. Preparation of tungsten iron carbide by ball milling, Proc. ANZIP annual condensed matter physics meeting; WaggaWagga, NSW (Australia), Monash Univ., Clayton, VIC(Australia), 154. Tsuchida, T., Suzuki, K., Naganuma, H., 2001. Low-temperature formation of ternary carbide Fe 3 M 3 C (M=Mo, W) assisted by mechanical activation. Sol. St. Ionics141 – 142, 623 – 631. Barona Mercado, W., Cuevas, J., Castro, I.Y., Fajardo, M., Pérez Alcázar, G.A., Sánchez Sthepa, H., 2007. Synthesis and characterization of Fe 6 W 6 C by mechanical alloying. Hyperfine Interact. 175, 49 – 54. Zhang, Z., Chen, Y., Zuo, L., Zhang, Y., Qi, Y., Gao, K., 2017. The effect of volume fraction of WC particles on wear behavior of in-situ WC/Fe composites by spark plasma sintering. Int. J. Refract. Met. Hard Mater. 69, 196 – 208. Eryomina, M.A., Lomayeva, S.F., Lyalina, N.V., Syugaev, A.V., Paranin, S.N., Tarasov, V.V., 2020. Structure and properties of mechanosynthesized W-Fe-C carbides. Mater. Today Proc. 25, 356-359. Kharanzhevskiy, E., Reshetnikov, S., 2014. Chromium oxide dissolution in steels via short pulse laser processing. Appl. Phys. A 115, 1469. Kostenkov, S.N., Kharanzhevskii, E.V., Krivilev, M.D., 2012, Determination of characteristics of laser radiation interaction with nanocomposite powder materials. Phys. Met. Metall. 113, 93. Eryomina, M.A., Lomayeva, S.F., Paranin, S.N., et al., 2017. Properties of the Ti-C-H- Сu composites obtained by mechanosynthesis using organic media. Letters on material. 7, 323-326. Tarasov, V.V., Lokhanina, S.Yu., Churkin, A.V. 2010. Ispytaniematerialovnaotnositel'nuyuiznosostoykost' namashinetreniya SRV-III [Testing of materials for relative wear resistance on friction machine SRV-III]. Zavodskayalaboratoriya. Diagnostikamaterialov [Industrial Laboratory], 76(4), 57-60.