A Combinatorial Approach for Assessing the Magnetic Properties of High Entropy Alloys: Role of Cr in AlCoxCr1-xFeNi

作者：Borkar Tushar; Chaudhary Varun; Gwalani Bharat; Choudhuri Deep; Mikler Calvin V; Soni Vishal; Alam Talukder; Ramanujan Raju V; Banerjee Rajarshi

来源：Advanced Engineering Materials, 2017, 19(8): 1700048.

DOI：10.1002/adem.201700048

A combinatorial assessment of composition-microstructure-magnetic property relationships in magnetic high entropy AlCoxCr1-xFeNi alloy (0x1) system has been carried out using compositionally graded alloys fabricated via laser additive manufacturing. At one end, the AlCoFeNi composition (x=1) consisted of equiaxed B2 grains, exhibiting very early stages of phase separation (only compositional partitioning) into Ni-Al rich and Fe-Co rich regions within grains of the B2 phase. At the other extreme, the AlCrFeNi composition (x=0) exhibited grains with pronounced spinodal decomposition, resulting in a B2+bcc microstructure with the degree of spinodal decomposition progressively increasing with Cr content in these AlCoxCr1-xFeNi alloys. While the saturation magnetization (M-s) monotonically increases six times from x=0 to x=1, the coercivity (H-c) variation is non-monotonic, increasing seven times from x=0 to x=0.4, and subsequently decreasing fourteen times from x=0.4 to x=1.0. The magnetic phase transition temperature (T-c) for these alloys also increases monotonically with increasing Co content with a second phase transition exhibited in a certain range of compositions between x=0.6 to x=0.8. Such substantial changes in the magnetization behavior and properties of magnetic high entropy systems opens possibilities of tuning these alloys for specific soft or hard magnetic component applications.

• 出版日期2017-8