Presentation Information
[P1-18]Influence of the infiltrating additives of R-Cu-Co type on magnetic hysteresis properties and intergrain exchange interaction of the Nd-Fe-B alloys
*Aleksandra A. Golubiatnikova1, Sergey V. Andreev1, Ilia A. Ivanov1, Arkadiy N. Shalaginov1, Alexey S. Volegov1 (1. UrFU (Russia))
Keywords:
Nd2Fe14B,permanent magnets,grain boundary infiltration,exchange interaction
The disadvantages of Nd2Fe14B phase are the low Curie temperature of 312 ℃ and high temperature coefficients of remanence and coercivity, leading to a significant decrease in the performance of neodymium magnets as the operating temperature increases. This fact makes it difficult to use neodymium magnets in strong demagnetizing fields at high operating temperature. This problem is solved by alloying the initial alloy with heavy rare-earth metals such as Dy and Tb, which leads to an increase Hc at room temperature and allows to keep its value acceptable at elevated operating temperatures, but significantly increases the cost and leads to a decrease in the value of residual magnetization. One of the ways of obtaining highly coercive permanent magnets with a relatively low content of REM is the process of intergrain infiltration, in which, on the one hand, there is a thickening of the grain-boundary phase, and on the other hand, heavy elements partially penetrate deep into the grains of the main phase, forming a core-shell structure.
In this work the influence of the composition of low-melting additives of REM-Cu-Co type (where REM = La, Ce, Nd, Gd and Tb) on magnetic hysteresis properties and inter-grain exchange interaction of rapidly quenched nanocrystalline hard magnetic alloy based on Nd2Fe14B compound is investigated.
According to the results of experimental studies of magnetic susceptibility and magnetization-temperature dependences, it was found that the intergranular exchange interaction constant decreased, but the exchange interaction of ferromagnetic type between grains is preserved. It was found that the use of any REM in the composition of a fusible additive leads to an increase in the coercivity. The obtained values of Hc show that using cheaper REMs (La, Ce and Gd) it is possible to increase the coercivity by 55 % compared to the initial one. Using Nd and Tb as additives it was possible to increase the coercivity up to 22 kOe and 33 kOe, respectively.
The work was financially supported by the Ministry of Science and Higher Education of the Russian Federation FEUZ-2024-0060.
In this work the influence of the composition of low-melting additives of REM-Cu-Co type (where REM = La, Ce, Nd, Gd and Tb) on magnetic hysteresis properties and inter-grain exchange interaction of rapidly quenched nanocrystalline hard magnetic alloy based on Nd2Fe14B compound is investigated.
According to the results of experimental studies of magnetic susceptibility and magnetization-temperature dependences, it was found that the intergranular exchange interaction constant decreased, but the exchange interaction of ferromagnetic type between grains is preserved. It was found that the use of any REM in the composition of a fusible additive leads to an increase in the coercivity. The obtained values of Hc show that using cheaper REMs (La, Ce and Gd) it is possible to increase the coercivity by 55 % compared to the initial one. Using Nd and Tb as additives it was possible to increase the coercivity up to 22 kOe and 33 kOe, respectively.
The work was financially supported by the Ministry of Science and Higher Education of the Russian Federation FEUZ-2024-0060.