Metal Amorphous Nanocomposite (MANC) Alloys and In-Line Manufacturing

Technical description

FeNi-based alloys, 20µm thick and 2.5cm wide were annealed with two different techniques to see property differences and ability to scale up. Conventional annealing used a preheated furnace at 480-540 °C for 30 min with air cooling. Flash annealing used a custom setup in which a ribbon was clamped between preheated, high-thermal-mass copper blocks for 1-7 s and then air quenched. Phase and grain structure were characterized by X-ray diffraction. Dynamic coercivity and permeability were measured at 2 kHz with a Brockhaus MPG 200 steel tester. Ductility was assessed with a newly designed semi-quantitative, scheme of shear cutting, manual tearing, and 180° bending, with five repeats per condition summed to a 0-45 brittleness score. Thermo-Calc Gibbs free energy calculations for the binary Fe-Ni system at 480 °C and above, using common and parallel tangent constructions, predicted FCC-dominant crystallization. Flash annealing gave FCC-dominant, finer-grained structures than conventional annealing. Coercivity decreased after flash annealing and remained ductile enough to wrap into a core. While conventional anneals increased coercivity and became too brittle to bend, restricting their use in continuous processing.

Why it matters

• Flash annealing allows tunability of magnetic and microstructural properties, and more ductile ribbon
• Seconds long flash annealing can lead to faster, continuous manufacturing at scale, in place of conventional batch anneals

Key publications

• L. Wewer, K. Byerly, S. Kernion and P. Ohodnicki, "FeNi-Based Nanocomposite Soft Magnetic Alloy Magnetic and Mechanical Property Tailoring Through Flash Annealing," 2023 IEEE International Magnetic Conference (INTERMAG), Sendai, Japan, 2023, pp. 1-5, doi: 10.1109/INTERMAG50591.2023.10265099.
• Journal paper will be published spring 27