1. Mihael Bruncko, University of Maribor, Faculty of Mechanical Engineering, Smetanova 17, SI-2000 Maribor, Slovenia, e-mail: and University of Leoben, Department of Physical Metallurgy and Materials Testing, Franz-Josef-Straße 18, A-8700 Leoben, Austria, e-mail:
2. Ivan Anzel, University of Maribor, Faculty of Mechanical Engineering, Smetanova 17, SI-2000 Maribor, Slovenia, e-mail:
3. Albert C. Kneissl, University of Leoben, Department of Physical Metallurgy and Materials Testing Franz-Josef-Straße 18, A-8700 Leoben, Austria, e-mail: