Influence of the composition of a boron-containing active medium in the form of a coating on the structure and properties of a diffusion layer on titanium parts

A comparative study of VT-1.0 titanium boriding, carboboronizing and borosiliconizing methods was carried out in order to increase wear resistance in aggressive environments at elevated temperatures. The microstructure of diffusion coatings was investigated, their thickness and microhardness were determined. Diffusion saturation of 10×10×25 mm VT-1.0 titanium samples was carried out from saturating coatings based on boron carbide. Process temperature of 950 °C, and saturation time of 1.5 h were used as saturation conditions. At the end of high-temperature exposure, samples were removed from the furnace and cooled in air to room temperature, cleaned from saturating coatings with wooden spatulas, and boiled in the soap and soda solution for 1 h. A continuous diffusion layer 80–100 μm thick forms on the titanium surface. The borosiliconized diffusion layer obtained by titanium saturation from the mixture of 45%B₄C–5%Na₂B₄O₇–22%Si–5%NaF–3%NaCl– 20%CrB₂ has a higher microhardness: 1520 HV_0.1 versus 1280 HV_0.1 for carboboride one and 1120 HV_0.1 for boride one. In this case, boride and carboboride coatings, obtained, respectively, by saturation from 45%B₄C–5%Na₂B₄O₇–5%NaF–25%Al₂O₃–20%CrB₂ and 70%B₄C– 5%Na₂B₄O₇–5%NaF–20%CrB₂ coatings have a pronounced zonal structure. The upper zone of these coatings having high microhardness also features high brittleness indicators, which makes it impossible to accurately measure microhardness distribution due to chipping and cracking at microhardness measurement points. The qualitative composition of coatings on titanium was studied by X-ray diffraction using the DRON-6 X-ray diffractometer in filtered CuK_α radiation (λ = 1.5418 Å) in the angle range of 2θ = 20÷80°. The diffusion coating exhibits reflections of titanium carbide, chromium and titanium borides, and a certain amount of the Cr₂Ti intermetallic compound. Boride phases of chromium and titanium refer to high boron phases with high specific boron content: TiB, CrB, Ti₂B₅, Ti₃B₄ и Cr₂B₃.

1. Baruwa A.D., Akinlabi E.T., Oladijo O.P. Surface coating processes: from conventional to the advanced methods (A short review). In: Selected articles from ICMMPE 2019. Advances manufacturing engineering. Lecture notes in mechanical engineering. Singapore: Springer, 2020. P. 483—494. https://doi.org/10.1007/978-981-15-5753-8_44.

2. Ovcharenko P.G., Makhneva T.M., Shabanova I.N., Terebova N.S. Composition of surface layers of titanium alloy after electrospark alloying. Metal Sci. Heat Treat. 2020. Vol. 62. P 195—198. DOI:10.1007/s11041-020-00553-w.

3. Hossam A. Kishawy, Ali Hosseini. Machining difficult-to-cut materials. Basic principles and challenges. Springer Intern. Publ. AG. Part of Springer Nature, 2019. https://doi.org/10.1007/978-3-319-95966-5.

4. Tyurnina Z.G., Tyurnina N.G. Formation of wearresistant and corrosion-resistant coatings on titanium. Fizika i khimiya stekla. 2012. Vol. 38. No. 6S. Р. 905—909 (In Russ.).

5. Li C., Li M.S., Zhou Y.C. Improving the surface hardness and wear resistance of Ti3SiC2 by boronizing treatment. Surface Coat. Technol. 2007. No. 201. Р. 6005—6011. DOI:10.1016/j.surfcoat.2006.11.008.

6. Lizhi Liu. Surface hardening of titanium alloys by gas phase nitridation under kinetic control: Diss. of PhD. Cleveland: Case Western Reserve University, 2005. URL: https://etd.ohiolink.edu/apexprod/rws_etd/send_file/send?accession=case1094223428&disposition=inline (accessed: 29.07.2021).

7. Liu Y., Xu X., Xiao Y., Niu T., Tabie T., Li Chong, Li Chen. High-temperature oxidation behavior of Al-modified boronized coating prepared on Ti—6Al—4V by thermal diffusion. J. Mater. Eng. Perform. 2020. Vol. 29. P. 6503—6512. DOI:10.1007/s11665-020-05170-5.

8. Matsushita M. Boronization and carburization of superplastic stainless steel and titanium-based alloys. Materials. 2011. Vol. 4. Р. 1309—1320. DOI:10.3390/ma4071309.

9. Li Y., Su K., Bai P. Effect of TiBCN content on microstructure and properties of laser cladding Ti/TiBCN composite coatings. Met. Mater. Int. 2019. Vol. 25. P. 1366—1377. DOI:10.1007/s12540-019-00287-2.

10. Kobeleva L.I., Bolotova L.K., Kalashnikov I.E., Mikheev R.S., Kolmakov A.G. Effect of microcrystalline boron particles on structure and tribological properties of welded B83 babbitt layers. Inorg. Mater.: Appl. Res. 2020. Vol. 11. P. 1—6. DOI:10.1134/S2075113320010207.

11. Ivanov S.G., Guriev A.M., Starostenkov M.D., Ivanova T.G., Levchenko A.A. Special features of preparation of saturating mixtures for diffusion chromoborating. Russ. Phys. J. 2014. Vol. 57. P. 266—269.

12. Ivanov S.G., Guriev M.A., Loginova M.V., Deev V.B., Guriev A.M. Boriding of titanium OT4 from powder saturating media. Russ. J. Non-Ferr. Met. 2017. Vol. 58. P. 244—249. DOI:10.3103/S1067821217030051.

13. Guryev A., Ivanov S., Guryev M., Mei S., Quan Z. Complex diffusion saturation of carbon steel 1045 with boron, chromium, titanium and silicon. IOP Conf. Ser.: Mat. Sci. Eng. 2021. Vol. 1100. P. 012048. DOI:10.1088/1757-899X/1100/1/012048.

14. Garmaeva I.A., Guriev A.M., Ivanova T.G. Comparative study of saturating power boriding media of different composition. Lett. Mater. 2016. Vol. 6. P. 262—265. DOI:10.22226/2410-3535-2016-4-262-265.

15. Hüseyin Ç., Kemal Ö.M., Hasan A., Mehmet L.A. Boriding titanium alloys at lower temperatures using electrochemical methods. Thin Solid Films. 2007. No. 515. Р. 5348—5352. DOI:10.1016/j.tsf.2007.01.020.

16. Song Jz., Tang W., Huang Jw., Wang Zk., Fan Xm., Wang Kh. Effects of boronizing treatment on microstructural development and mechanical properties of additively manufactured TC4 titanium alloys. J. Iron Steel Res. Int. 2019. Vol. 26. P. 329—334. DOI:10.1007/s42243-018-0216-y.

17. Fenghua L., Xiaohong Y., Jinglei Z., Zhanguo F., Dianting G., Zhengping X. Growth kinetics of titanium boride layers on the surface of Ti6Al4V. Acta Metall. Sin. A. 2010. Vol. 23. Р. 293—300.

18. Ivanov S.G., Guryev M.A., Guryev A.M., Romanenko V.V. Phase analysis of boride complex diffusion layers on carbon steels using color etching. Fundamental’nye problemy sovremennogo materialovedeniya. 2020. Vol. 17. No 1. P. 74—77 (In Russ.).

19. Kazakov A.A., Ryaboshuk S.V., Lyubochko D.A., Chigintsev L.S. Research on the origin of nonmetallic inclusions in high-strength low-alloy steel using automated feature analysis. Microsc. Microanal. 2015. Vol. 21. P. 1755—1756. DOI:10.1017/S1431927615009551.

20. Vander Voort G.F., Pakhomova O., Kazakov A. Evaluation of normal versus non-normal grain size distributions. Mater. Perform. Character. 2016. Vol. 5. P. 521—534. DOI:10.1520/MPC20160001.

21. ASM Handbook. Vol. 9: Metallography and microstructures. Ed. G.F. Vander Voort. ASM International, 2004. DOI:10.31399/asm.hb.v09.9781627081771.

22. Kazakov A., Kiselev D. Industrial application of thixomet image analyzer for quantitative description of steel and alloy’s microstructure. Metallogr. Microstruct. Anal. 2016. Vol. 5. P. 294—301. DOI:10.1007/s13632-016-0289-6.

23. Vander Voort G.F. Computer-aided microstructural analysis of specialty steels. Mater. Character. 1991. Vol. 27. P. 241—260. DOI:10.1016/1044-5803(91)90040-B.

24. Kazakov A.A., Kiselev D.V., Kazakova E.I. Methodological features of microstructural heterogeneity estimation by the thickness of steel plates. Chernye Metally. 2021. No. 7. P. 65—75. DOI:10.17580/chm.2021.07.06.

25. Kazakov A., Kovalev P., Ryaboshuk S. Metallurgical expertise as the base for determination of nature of defects in metal products. CIS Iron Steel Rev. 2007. Vol. 1—2. P. 7.

26. Liu Y., Chai L., Ma X., Cui Y., Chen Z., Xiang Z. Effect of boron addition methods on microstructure and mechanical properties of a near-α titanium alloy. In: Physics and engineering of metallic materials. CMC 2018. Springer proceedings in physics. Vol. 217. Singapore: Springer, 2019. DOI:10.1007/978-981-13-5944-6_6.

27. Chkhartishvili L., Tsagareishvili O., Mikeladze A., Chedia R., Kvatchadze V., Ugrekhelidze V. Highly stable boron carbide based nanocomposites. In: Handbook of nanomaterials and nanocomposites for energy and environmental applications. Springer, Cham., 2020. DOI:10.1007/978-3-030-11155-7_81-1.

28. Jiancheng G. High-pressure sintering of boron carbidetitanium diboride composites and its densification mechanism. J. Wuhan Univer. Technol-Mater. Sci. 2020. Vol. 35. DOI:10.1007/s11595-020-2264-y.

29. Biplab Sarma. Accelerated kinetics and mechanism of growth of boride layers on titanium under isothermal and cyclic diffusion: Diss. of PhD. Utah: University of Utah, 2011. URL: https://www.proquest.com/docview/858204585 (accessed: 29.07.2021).

30. Huang Y.G., Chen J.R., Zhang M.L., Zhong X.X., Wang H.Q., Li Q.Yu. Electrolytic boronizing of titanium in Na2B4O7—20%K2CO3. Mater. Manufact. Proces. A. 2013. Vol. 28. P. 1310—1313.

31. Vadchenko S.G. Dependence of the burning rates of tapes of Ti + xB mixtures on boron concentration. Combus. Explos. Shock Waves. 2019. Vol. 55. P. 177—183. DOI:10.1134/S0010508219020060.

32. Aich S., Chandran K.S., Ravi Ch. TiB Whisker coating on titanium surfaces by solid-state diffusion: synthesis, microstructure, and mechanical properties. Metall. Mater. Trans. 2002. Vol. 33A. Р. 3489—3498.

33. Malkin I., Klyuev V., Popov D., Ryazantseva A., Savenko V. Physical and chemical mechanics of the synthesis of boron-containing composite powders. Russ. J. Phys. Chem. A. 2020. Vol. 94. P. 490—495. DOI:10.1134/S0036024420030206.

34. Sanders A., Tikekar N., Lee C., Chandran K. Surface hardening of titanium articles with titanium boride layers and its effect on substrate shape and surface texture. J. Manuf. Sci. Eng. 2010. Vol. 131. Р. 1—8.