Radio‐Frequency Rapid Thermal Processing Enabling Spatial Phase Transformation and Nanocrystallization of Soft Magnetic Amorphous Alloys
Abstract
Thermal processing of soft magnetic amorphous and nanocrystalline alloys is explored under the influence of radio‐frequency induction‐heating techniques. Direct induction‐heating concepts based on longitudinal and transverse flux heating are examined and the details of electromagnetic fields interaction with metallic strips are discussed by analytical calculations as well as finite element analysis. Initial experimental results confirming spatial control of phase transformations and nanocrystallization within a single strip of Finemet Fe‐based amorphous ribbons are reported. The degree to which primary and secondary crystallization temperature are achieved depends on the spacing between the ribbon relative to the induction coil as well as the coil design and configuration. For transverse coil configurations, the local temperature and therefore microstructural evolution is different across the lateral dimension of processed ribbons, with reduced gap sizes producing enhanced peak temperatures and larger temperature distributions with greater spatial variation in microstructure. In addition, indirect susceptor‐based induction heating under tension is performed and the impact of microstructure is demonstrated. Herein, potential for exploiting spatially optimized phase transformations is illustrated through electromagnetic field–assisted processing in a scalable manufacturing process with amorphous and nanocrystalline soft magnetic alloys.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- May 12, 2022
- Source ID
- 10.1002/adem.202200208
Entities
People
- Ahmed Talaat
- David W. Greve
- Kevin Byerly
- Michael E. Mchenry
- Paul R. Ohodnicki Jr.
- Shibo Tan
- Tyler Paplham
Organizations
- Carnegie Mellon University
- Office of Naval Research
- United States Department of Energy
- University of Pittsburgh