1. Faculty of Special Technology, Alexander Dubcek University of Trenčín, 911 06 Trenčín, Slovakia
2. Private Joint Stock Company, Novokramatorsky Mashinostroitelny Zavod, 84305 Kramatorsk, Ukraine
3. Faculty of Industrial Technologies, Alexander Dubcek University of Trenčín, 020 01 Púchov, Slovakia
4. Institute of Materials and Machine Mechanics, SAS, Dúbravská cesta 9/6319, 845 13 Bratislava, Slovakia