Feasible piezomagnetic coefficients of Fe65Co35 alloys with Cr addition

The effect of Cr addition to Fe65Co35 alloy on magnetostriction, mechanical properties and magnetomechanical properties were accessed. Based on the high saturation induction and permeability of FeCo alloys, this study analyzed the potential of Fe 65 Co 35 alloys with Cr as a cost-effective alternative for piezomagnetic applications. Chromium was added to this alloy at concentrations of 0.5 wt.% and 0.7 wt.% (Fe65Co35-0.5Cr and Fe65Co35-0.7Cr). The samples were arc-melted, hot rolled and annealed. A comprehensive characterization was performed of the microstructure, magnetic, mechanical, and magnetomechanical properties. Despite the small Cr content difference of only 0.2 wt.%, a significant microstructural variation was observed, with abnormal grain growth occurring (AGG) in the alloy containing 0.5 wt.% Cr. The Fe65Co35-0.7Cr alloy exhibited the best soft magnetic properties and the highest magnetostriction of 53ppm . However, the highest piezomagnetic sensitivity reached was 6.2 kA•m⁻¹.MPa -1 for the Fe 65 Co 35 -0.5Cr alloy. The source of differences of piezomagnetic behaviors was found to be associated to different internal stress levels