Laser Nitriding of Titanium Alloys

V. V. Girzhon$^{1}$, V. V. Yemelianchenko$^{1}$, O. V. Kushch$^{1}$, I. O. Bykov$^{2}$

$^{1}$Zaporizhzhya National University, 66 Zhukovsky Str., UA-69600 Zaporizhzhya, Ukraine
$^{2}$Motor Sich JSC, 15 Motorostroiteley Ave., UA-69068 Zaporizhzhya, Ukraine

Received: 18.04.2019; final version - 09.11.2019. Download: PDF

The structural and phase states of superficial layers of technically pure titanium VT1-0 and industrial titanium alloy VT6 after laser treatment in different gaseous environments are investigated using X-ray and metallographic methods. As established, the laser melting of technically pure titanium VT1-0 in all cases leads to structural changes in the surface layers of treated samples, as a result of which the microhardness of the melted surfaces increases in 1.3–1.4 times (in the atmosphere of argon), in 3.0–3.1 times (under atmospheric conditions) and 4.4–4.5 times (under nitrogen atmosphere). As a result of the laser melting of the doped titanium alloy VT6 in the atmosphere of argon, a decrease in the values of microhardness due to the formation of the martensitic phase is observed regardless of the influence of alternative factor, namely, increasing the degree of structure dispersion. During the laser melting of the titanium alloy VT6 in the atmosphere of air and nitrogen, the formation of high-strength cubic type titanium nitride TiN, the formation of a supersaturated interstitial solid solution of nitrogen and oxygen in $\alpha$-Ti, and the increased degree of structural dispersion are observed. All of the above factors lead to an increase in the values of microhardness of 1.3–1.4 times and 1.4–1.5 times after laser melting in the air and nitrogen atmospheres, respectively. Therefore, the technique of laser surface processing presented in this article is an effective method for the surface treatment of titanium alloys, since it has a qualitative effect on the structure, which in turn leads to an improvement in the mechanical characteristics of the surface layers.

Key words: laser treatment, melting zone, martensitic transformation, microhardness, phase composition.

URL: http://mfint.imp.kiev.ua/en/abstract/v42/i04/0553.html

DOI: https://doi.org/10.15407/mfint.42.04.0553

PACS: 61.80.Ba, 62.20.Qp, 64.60.My, 81.30.Kf, 81.40.Gh, 81.65.Lp

Citation: V. V. Girzhon, V. V. Yemelianchenko, O. V. Kushch, and I. O. Bykov, Laser Nitriding of Titanium Alloys, Metallofiz. Noveishie Tekhnol., 42, No. 4: 553—563 (2020) (in Ukrainian)


REFERENCES
  1. G. D. Revankar, R. Shetty, S. S. Rao, and V. N. Gaitonde, J. Mater. Res. Technol., 6, No. 1: 13 (2017). Crossref
  2. S. Malinov, A. Zecheva, and V. Sha, Metallovedenie i Termicheskaya Obrabotka Metallov, No. 7: 21 (2004) (in Russian).
  3. I. M. Pohrelyuk, M. V. Kindrachuk, and S. M. Lavrys', Physicochemical Mechanics of Materials, No. 1: 56 (2016) (in Ukrainian). Crossref
  4. I. V. Gajvoronskij, V. V. Girzhon, A. A. Skrebcov, and A. V. Ovchinnikov, MiTOM, No. 1: 53 (2014) (in Russian).
  5. V. V. Girzhon and A. V. Ovchinnikov, MiTOM, No. 12: 24 (2016) (in Russian).
  6. V. V. Girzhon, O. V. Smolyakov, and O. F. Zdorovets, Metallofiz. Noveishie Tekhnol., 39, No. 4: 507 (2017) (in Russian). Crossref
  7. R. Filip, J. Achievements in Materials and Manufacturing Engineering, 15, Nos. 1-2: 174 (2006).
  8. U. Zwicker, Titan und Titanlegierungen (Springer Verlag: 2013).
  9. D. S. Badkar, K. S. Pandey, and G. Buvanashekaran, Int. J. Material Science, 3, No. 4: 239 (2009).
  10. C. Xuekand, W. Can, W. Rui, G. Wantu, Y. Jianping, C. Shengzhu, W. Yinling, and H. Weihua, Surface Coatings Technology, No. 201: 4843 (2007).
  11. V. F. Bashev, O. E. Beletskaya, N. A. Korovina, N. A. Kutseva, and A. A. Lysenko, Phys. Chem. Solid State, 6, No. 1: 141 (2005).