High-temperature magnetization and bulk magnetostriction investigation of Ti and Nb addition to Fe₇₀Co₃₀ alloy

Author(s)

Froes, Fernando ; Bormio-Nunes, Cristina

• Document type: Journal article
• Source: Journal of Materials Science; v. 59, n. 4, p. 13-pg., 2024-01-11.

Abstract

Lowering the Co content of the equiatomic Fe-Co alloys is of economic interest. The greatest interest is the application on electric motors, since the high-saturation magnetization level provides higher torques. In the present work, Fe70Co30 alloys with the addition of Ti and Nb were studied to improve magnetic properties. The alloys (Fe0.7Co0.3)(97)Ti-3, (Fe0.7Co0.3)(99)Nb-1, and (Fe0.7Co0.3)(96)Ti3Nb1 were produced, and the effects of Ti and Nb addition on the Fe70Co30 alloy microstructure and magnetic properties were studied. The addition of 1% of Nb + 3% of Ti to the Fe70Co30 alloy reduced most of the saturation magnetization polarization (from 2.34 to 2.14 T at 300 K), but the saturation magnetic polarization P-s is almost the same of pure Fe, although the Curie temperature is 195 K higher. The addition of only Ti or only Nb resulted in P-s even higher than 2.14 T and (Fe0.7Co0.3)(99)Nb-1 presents the highest P-s. The quaternary alloy has the lowest value of H-c = 362 A m(-1) and lambda(s) = 54 x 10(-6), though the (Fe0.7Co0.3)(99)Nb-1 has the highest H-c = 1790 A m(-1), the highest P-s = 2.23 T, and the lowest saturation magnetostriction lambda(s) = 42.7 x 10(-6). The alloy's spin wave stiffnesses were determined from saturation magnetization versus temperature curves. (AU)

• FAPESP's process: 21/06350-0 - Development of Fe-Co alloys with the addition of Ti and Cr for applications in high energy performance electric machines
• Grantee: Cristina Bormio Nunes
• Support Opportunities: Regular Research Grants