The paper describes the influence of severe plastic deformation (SPD) on the crystallization of the amorphous rapidly quenched Ti-Ni and Nd-Fe-B alloys. It has been revealed that the SPD by high pressure torsion (HPT) at room temperature leads to formation of nanocrystals in these initially amorphous alloys. The subsequent annealing of these HPT-processed alloys leads to formation of homogeneous nanocrystalline structure. The SPD processing of the amorphous alloys can be used as a novel method for producing bulk nanocrystalline materials.
The control of nanocrystal formation in amorphous alloys is of particular importance for the development of advanced nanocrystalline materials. In the present study, the authors succeeded in controlling α-Fe and Nd2Fe14B nanocrystallization processes in amorphous Nd9Fe85B6 by a combination of severe plastic deformation at room temperature and subsequent thermal annealing. The α-Fe∕Nd2Fe14B nanocomposite magnets prepared by this approach possess homogeneously distributed nanocrystals with a small size, 15nm for α-Fe phase and 26nm for Nd2Fe14B, and therefore show enhanced magnetic properties as compared to those prepared by directly annealing amorphous Nd9Fe85B6.
A new technique of continuous severe plastic deformation (SPD)-processing, i.e. ECAP (equal
channel angular pressing)-Conform is applied for the first time to produce long-length rods of
commercial purity Ti with ultrafine-grained structure. The paper reports on the results of
investigation of the microstructure and mechanical properties of Ti rods processed by ECAPConform
and the following wire drawing.
In general, there is a trade-off between magnetization and coercivity in nanocomposite magnets. Here, we demonstrate a simultaneous enhancement of both the magnetization and coercivity in bulk α-Fe/Nd2Fe14B nanocomposite magnets prepared via a severe plastic deformation (SPD) compared with thermally annealed magnets. The enhanced magnetization results from a high fraction (>30%) of α-Fe phase induced by SPD, while the increase in coercivity from 4.6 to 7.2 kOe is attributed to an enhancement in domain wall pinning strength. This study shows an increase in energy product is possible in the nanocomposite magnets for a large inclusion of soft-magnetic phase.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.