Nanocomposites and nanomaterials

Using of high-voltage potential in pulsed form for obtaining nanostructural state of vacuum-arc TiN condensates
Pinchuk N. V.1, Sobol’ O. V.1, Stolbovoy V.A.2
1 National Technical University “Kharkiv Polytechnic Institute”, 2, Kyrpychova str., 61002 Kharkiv, Ukraine.
E-mail: spiritnata@gmail.com
2 National Science Center Kharkov Institute of Physics and Technology, 
1, Akademicheskaya St., Kharkov, 61108, Ukraine.

In the early 1990s, a new idea was pursued, namely combining implantation with deposition, such as to create almost any desirable elemental composition profile. A preferred “condensable” plasma was found in cathodic-arc generated plasma because such plasma is characterized by a very high degree of ionization and the presence of multiply charged ions, thus application of substrate bias is very efficient. One of the most important parameters is the average energy of the bombarding particles during high-voltage impulse stimulation [1].
In this work titanium nitride coatings were obtained on the modernized Bulat-6 installation, which is additionally equipped with a generator of high-voltage pulses applied to the substrate during the deposition process. The pressure of the nitrogen atmosphere is PN = 1 • 10-3 ... .2.7 • 10 -2 Pa. The magnitude of the negative constant bias potential was Ub = (-27 ... -300) V, and the high-voltage pulsed negative potential Uip = (-800 ... -2000) V (with a frequency of 7 kHz and an exposure duration of 4, 10 and 16 μs). 
Computer simulation of ion-plasma implantation was performed using the TRIM program in the “Monolayer Collision Steps / Surface Sputtering” mode.
It is shown that the supply of high-voltage pulsed bias potential increases the mobility of particles and leads to relaxation processes. The last ensures a decrease in the growth stresses of compression and the disorientation of the crystallite grains with a small constant Ub. The reasons for the observed structural changes in titanium nitride coatings were analyzed based on the mechanism of formation of the surface layers of vacuum-arc coatings under conditions of implantation processes stimulated by applying a negative potential to the substrate.

1.	Sobo l’ O.V., Andree, A.A., Grigoriev S.N., Aleshin S.V., Stolbovoi V.A. Effect of high-voltage pulses on the structure and properties of titanium nitride vacuum-arc coatings // Metal Science and Heat Treatment.-2012.-54, N 3-4.-P. 195-203.