Formation of FeNi withL1₀-ordered structure using high-pressure torsion

AbstractFeNi with the L10-ordered structure is formed over an astronomical timescale in meteorites. In this study, severe plastic deformation using high-pressure torsion (HPT) is employed for the production of the L10 structure in the laboratory. Its formation is confirmed by X-ray diffraction analysis and transmission electron microscopy. Processing of elemental nanopowders by HPT is an effective method for the formation of the L10 phase, which is enhanced by the addition of Co to FeNi or annealing after HPT. The formation of the phase must be associated with enhanced diffusion through HPT.Keywords: severe plastic deformation (SPD)ultrafine grains (UFG)phase transformationtransmission electron microscopyenhanced diffusion AcknowledgementsThis study was supported by the Japan Science and Technology Agency (JST) under Collaborative Research Based on Industrial Demand 'High Performance Magnets: Towards Innovative Development of Next Generation Magnets'. The TEM observation was performed using the facility of the HVEM laboratory of Kyushu University with a concurrent support by a Grant-in-Aid for Scientific Research from the MEXT, Japan, in Innovative Areas 'Bulk Nanostructured Metals' (No. 22,102,004).