Effect of hot deformation on texture and magnetic properties of Sm-Co and Pr-Co alloys

Nanocrystalline PrCo(5), SmCo(5) and Sm(2)(Co,Fe,Mn)(17) alloys were subjected to a high-degree plastic deformation at 950 degrees C with the height reduction ranging from 70% to 95%. With increasing degree of deformation, the PrCo(5) and SmCo(5) magnets showed improvement of the deformation-induced [0 0 1] texture. The PrCo(5) alloys, known to develop a superior texture at the lower degrees of deformation, showed only modest improvement and their magnetic performance was undermined by a low coercivity. The SmCo(5) alloys had their texture markedly enhanced and, after height reduction by 94.5%, they exhibited a remanence of 8.6 kG, maximum energy product of 18 MGOe and an intrinsic coercivity of 22.8 kOe. No induced texture was found in the alloys based on the Sm(2)Co(17) structure. The microstructures of the hot-deformed alloys were studied with a transmission electron microscopy, and possible mechanisms of the texture development in the RCo(5) alloys (R = Pr, Sm) are briefly discussed. (C) 2011 Elsevier BY. All rights reserved.