Ultrahigh coercivity and excellent thermal stability of hot-deformed Nd-Fe-B magnets by the diffusion of (Pr,Nd)-Dy-Cu-Al

The effects of the addition of (Pr0.25Nd0.75)10Dy80Cu5Al5 alloy powders on the magnetic properties and microstructure of the hot-deformed Nd-Fe-B magnets were investigated in this work. Through the addition of (Pr0.25Nd0.75)10Dy80Cu5Al5, an ultrahigh coercivity of 3.14 T was obtained in a 6-mm-thick hot-deformed magnet, and the temperature coefficient of coercivity and remanence were improved from -0.475%/& DEG;C and -0.145%/& DEG;C to -0.383%/& DEG;C and -0.110%/& DEG;C at 20 -180 & DEG;C, respectively, showing the excellent thermal stability. Microstructure observations indicated that the formation of thick nonferromagnetic intergranular phase, the reduction of grain size and aspect ratio and the formation of the (Nd,Pr,Dy)2Fe14B main phase were achieved after the addition of (Pr0.25Nd0.75)10Dy80Cu5Al5, which were the main reasons for the enhance-ment of coercivity and thermal stability.& COPY; 2023 Elsevier B.V. All rights reserved.

Automated summary

The effects of adding (Pr0.25Nd0.75)10Dy80Cu5Al5 alloy powders on the magnetic properties and microstructure of hot-deformed Nd-Fe-B magnets were investigated. The addition of (Pr0.25Nd0.75)10Dy80Cu5Al5 resulted in an ultrahigh coercivity of 3.14 T in a 6-mm-thick hot-deformed magnet, and improved the temperature coefficient of coercivity and remanence at 20-180℃, indicating excellent thermal stability. Microstructure observations showed that the addition of (Pr0.25Nd0.75)10Dy80Cu5Al5 led to the formation of thick nonferromagnetic intergranular phase, reduced grain size and aspect ratio, and the formation of the (Nd,Pr,Dy)2Fe14B main phase, which were the main reasons for the enhancement of coercivity and thermal stability.