1. Dept. of Material Science, College of Dunaújváros, H-2400, Táncsics M. St. 1/A, Dunaújváros, HU
2. Dept. of Materials Science and Engineering, Budapest Univ. of Technology and Economics, H-1111, Bertalan L. St. 7, Budapest, HU (Corresponding author), e-mail: bereczkip@mail.duf.hu
3. Dept. of Applied Mechanics, Budapest Univ. of Technology and Economics, H-1111, Műegyetem rkp. 5, Budapest, HU.
4. Dept. of Materials Science and Engineering, Budapest Univ. of Technology and Economics, H-1111, Bertalan L. St. 7, Budapest, HU.
5. Centre for Energy Research, Institute of Technical Physics and Materials Science, H-1121, Konkoly Thege M. St. 29-33, Budapest, HU.