X-ray diffraction and microstructural studies in 2 : 17 type Sm–Co magnetic alloys containing Fe, Cu, and Zr

Abstract

X-ray diffraction and microstructural studies were carried out on 2 : 17 type Sm–Co alloys containing Fe, Cu, and Zr (13–14 at.% Sm, 57–60 at.% Co, 20–22 at.% Fe, 4 at.% Cu, and 3 at.% Zr) in as-cast and heat-treated conditions. Microstructural studies revealed that the as-cast alloys contain three phases. It was observed that the samples subjected to sintering at 1463 K for 45 min followed by a solution treatment at 1448 K for 1 h resulted in nearly a single-phase, rhombohedral crystal structure (Th2Zn17-type). Subsequent isothermal aging at 1123 K and ramp-cooling to 673 K resulted in a mixture of Sm2Co17- and SmCo5-type phases with the former as major phase. It was also found that samples (Sm > 13 at.%) sintered at temperatures >1463 K showed incipient melting and multiphase formation.