The decomposition process mechanisms have been investigated in a Fe50Au25Pd25 (at.%) alloy processed by severe plastic deformation. Phases were characterized by X-ray diffraction and microstructures were observed using transmission electron microscopy. In the coarse grain alloy homogenized and aged at 450circC, the bcc \alpha-Fe and fcc AuPd phases nucleate in the fcc supersaturated solid solution and grow by a discontinuous precipitation process resulting in a typical lamellar structure. The grain size of the homogenized FeAuPd alloy was reduced in a range of 50 to 100nm by high pressure torsion. Aging at 450circC this nanostructure leads to the decomposition of the solid solution into an equi-axed microstructure. The grain growth is very limited during aging and the grain size remains under 100nm. The combination of two phases with different crystallographic structures (bcc \alpha-Fe and fcc AuPd) and of the nanoscaled grain size gives rise to a significant hardening of the alloy
@article{arxiv.0901.1191,
title = {Decomposition process in a FeAuPd alloy nanostructured by severe plastic deformation},
author = {Xavier Sauvage and Abdelahad Chbihi and Dmitry Gunderov and E. V. Belozerov and A. G. Popov},
journal= {arXiv preprint arXiv:0901.1191},
year = {2009}
}