Microstructure and Thermal Stability of Ultra Fine Grained Mg and Mg-Gd Alloys Prepared by High-Pressure Torsion


Article Preview

Bulk samples of pure Mg and Mg-Gd alloys were prepared by high-pressure torsion (HPT). The HPT made samples exhibit ultra fine grained (UFG) structure with grain size around 100 nm. Results of microstructure investigations of the UFG samples obtained by positron lifetime (PL) spectroscopy, transmission electron microscopy (TEM) and X-ray diffraction (XRD) are presented. In particular, lattice defects introduced by HPT were characterized. The data obtained at atomistic level are compared with macroscopic properties given by microhardness measurements.



Edited by:

Jaroslav Pokluda




J. Čížek et al., "Microstructure and Thermal Stability of Ultra Fine Grained Mg and Mg-Gd Alloys Prepared by High-Pressure Torsion", Materials Science Forum, Vol. 482, pp. 183-186, 2005

Online since:

April 2005




[1] P. Vostrý, B. Smola, I. Stulíková, F. von Buch, B.L. Mordike: phys. stat. sol. (a) Vol. 175 (1999), p.491.

DOI: https://doi.org/10.1002/(sici)1521-396x(199910)175:2<491::aid-pssa491>3.0.co;2-f

[2] R.Z. Valiev, R.K. Islamgaliev, I.V. Alexandrov: Prog. Mat. Sci. Vol 45 (2000), p.103.

[3] F. Bečvář, J. Čížek, L. Lešťak, I. Novotný, I. Procházka, F. Šebesta, Nucl. Instr. Meth. A Vol. 443 (2000), p.557.

[4] I. Procházka, I. Novotný, F. Bečvář, Mat. Sci. Forum Vol. 225-257 (1997), p.772.

[5] M.J. Puska, R.N. Nieminen, J. Phys. F: Met. Phys. Vol. 13 (1983), p.333.

[6] P. Hautojärvi, C. Corbel, in: Proceedings of the International School of Physics Enrico Fermi, Course CXXV, (Ed. A. Dupasquier, A.P. Mills), IOS Press, Varena 1995, p.491.

[7] M. Fahnle, B. Meyer, J. Mayer, J.S. Oehrens, G. Bester, in: Diffusion Mechanisms in Crystalline Materials (Ed.: Y. Mishin et al. ) MRS Symposia Proceedings No. 527, p.23.

[8] J. Čížek, I. Procházka, F. Bečvář, I. Stulíková, B. Smola, R. Kužel, V. Cherkaska, R.K. Islamgaliev, O. Kulyasova, to be submitted.

[9] J. Čížek, I. Procházka, G. Brauer, W. Anwand, R. Kužel, M. Cieslar, R.K. Islamgaliev, phys. stat. sol. (a) Vol. 195 (2003), p.335. r (mm).

DOI: https://doi.org/10.1002/pssa.200305929

1 2 3 4 I2 (%).

[60] [65] [70] [75] [80] [85] [90] [95] r (mm).

1 2 3 4 5 Hv (MPa).

500 1000 1500 2000 2500 3000 a) b) Fig. 2: Dependence of a) microhardness b) relative intensity of the PL defect component on the radial distance r from the center of sample. Full circles - HPT deformed Mg-10wt. %Gd, open circles - HPT deformed Mg.