Structure of an alloy based on SmCo5 after disproportionation-recombination

Abstract

By using the X-ray phase diffraction, metallographic, and micro-X-ray spectral analyses, we study the procedure of solid hydrogenation, disproportionation, desorption, and recombination in KS37 alloy formed by the SmCo5 and SmCo3 phases for $$P_{H_2 } $$ ≈ 4 MPa at 1158°K. The alloy disproportionates in hydrogen into a mixture of samarium hydride and cobalt with grain sizes ≤ 1 µm. The process of recombination ends by the restoration of the original phases accompanied by the formation of a fine-grained structure of the SmCo3 phase. As a result, the amount of this phase decreases. The procedure of holding of the alloy for 55 min in the course of recombination leads to the formation of a structure with elongated grains.