Nanostructured surfaces

The effect of treatment in a carbon-containing gas medium on the hardness of near-surface layers of VT1-0 titanium alloy
V.S. Trush , A.G. Luk’yanenko
Karpenko Physico-mechanical Institute the National Academy of Sciences of Ukraine, str. Naukova, 5 Lviv, 7906, Ukraine
E-mail: trushvasyl@gmail.com

Titanium alloys due to their inherent high complex of physical, chemical and mechanical properties are unique materials for many industries. [1-2]. A feature of titanium is its high reactivity with the interstitial elements (oxygen, nitrogen and carbon). The saturation regime was as follows. The titanium was heated in a vacuum of P = 26.6 mPa to the temperature T = 750°С, then a gas mixture (Ar + 16.7% C3H8) was added to the pressure P = 0.106 Pa, the partial pressure of propane was pC3H8 = 18 mPa. After the endurance of τ = 1, 3, 5 hours, the chamber was evacuated and the samples cooled with the furnace.
	
Fig. 1. Distribution of hardness in the near-surface layers of the VT1-0 titanium, depending on the duration of carburizing at 750°C: 1 – 1 h.; 2 – 3 h.; 3 – 5 h.	
It is established that an increase of the isothermal exposure of VT1-0 titanium at the temperature T = 750°C leads to an increase in hardness of the near-surface layers. Such results do not contradict the thermodynamic calculations, which are given in the literature.
1. Lutjering G. Titanium / Gerd Lutjering, James C. Williams // 2nd edition, Springer-Verlag Berlin Heidelberg, 2007. – 438 p.
2. Hideki F. Application of titanium and its alloys for automobile parts / F. Hideki, T.Kazuhiro, Ya. Yoshito // Nippon Steel Technical Report, 2003., 88. Р. 70-75.