Magnetic properties of SmCo₅ alloy fabricated by laser sintering

Samarium cobalt magnets have attracted significant attentions due to their promising ferromagnetic material properties. However, their development is limited based on the difficulties experienced while fabricating them into flexible shapes. These limitations are mainly due to high thermal sensitivity, processing constraints, easy oxidation and phase distortion of magnetic materials. Laser sintering, as one of the most outstanding additive manufacturing methods, is a promising candidate for building metal or alloy materials into 3D structures. While the shape and size requirement of pre-sinter powder as raw materials and thermal sensitivity of magnetic materials make ferromagnetic materials still suffering comprehensive challenge in fabrication for 3D structure by using laser sintering. In this research, a 3D part cylindrical shape using SmCo₅ materials was successfully fabricated through laser sintering. In this regard, the influence of different parameters on laser sintering of materials’ crystal structure and magnetic properties was fully studied. Parameters such as laser power, scanning speed, sintering times and hatch space were optimized for obtaining outstanding crystallization and optimal magnetic behavior. It was found that samples sintered in 0.01 inch hatch space obtained better crystallization and magnetic properties than those of samples sintered in 0.014 inch hatch space. Furthermore, the optimized parameters for laser sintering of SmCo₅ powders were 150 W, 50 inch/min and one-time sintering. The magnetic properties, such as coercivity (1586.4 Oe) and saturation magnetization (83.5 emu/g), maintained high level after laser sintering compared to that of the purchased ones (1589.4 Oe and 102.6 emu/g).