Severe Plastic Deformation of Iron-Cobalt-Vanadium Alloys

摘要

Severe mechanical deformation in addition to thermal processing can be used to produce microstructural refinement in iron-cobalt-vanadium alloys. As an example, significant grain refinement through Equal Channel Angular Extrusion (ECAE), also known as Equal Channel Angular Pressing (ECAP), at high temperatures was demonstrated in bulk Hiperco soft magnetic alloy. The ECAE material exhibited high strength levels comparable to Hiperco sheet and the ductility was higher than heat treated conventional bar with large grain size. The increase in ductility was attributed to small grain size and the disordered phase that may co-exist with the ordered phase. In addition, the ECAP material also displays good magnetic properties, with relatively high magnetic saturation as shown in the B-H curve. The heat treatment after ECAP improves magnetic performance, with some tradeoff in mechanical properties. Therefore, with proper choice of post-ECAP heat treatment, an optimum combination of mechanical and magnetic performance can be achieved for a desired application, such as in solenoid switches, electric motors, and generators.