Accelerated study of magnetic Fe-Co-Ni alloys through compositionally graded spark plasma sintered samples

Abstract

Soft magnets are extensively deployed in rotating electric machines. Accelerated development of new high Curie temperature, mechanically strong, magnetically soft magnets is urgently needed for next generation rotating electrical machines. The ternary Fe-Co-Ni alloy system was investigated. Spark plasma sintering (SPS) was employed to process compositionally graded (Ni-21Fe)-xCo samples. A combinatorial assessment of structural, magnetic, mechanical and electrical properties of sample sections was performed. Co-lean alloys exhibited a good combination of magnetic, mechanical, and electrical properties but low Curie temperatures. On the other hand, Co rich alloys exhibited elevated Tc, high Ms, and large hardness. An alloy library with a wide range of properties, Ms: 100–150 emu/g, Hc: 0.8–30 Oe, Tc: 571–1108 °C, ρ: 9–12.9 μΩ-cm, nanohardness: 0.96–1.56 GPa was developed. Thus, SPS processed samples can be employed for the accelerated screening of magnetic materials.