Infiltration of Die-Upset Nd-Fe-B Magnets With Mischmetal Eutectic Alloys

摘要: In recent years, infiltration of hot-deformed Nd-Fe-B magnets with liquid Nd- and Pr-rich alloys has been intensively studied as a cost-effective way increasing the magnet coercivity $H_{{\text{c}}}$ and, ultimately, its maximum operating temperature. this letter, similar improvement is obtained through commercial die-upset eutectic based on inexpensive Ce52La28Nd15Pr5 mischmetal (MM). After being infiltrated 10 wt% MM85Fe15, MM85Al 15, MM70Cu30 at 700 °C, exhibited an $H_{c}$ that was both higher more temperature stable than before treatment. For example, after MM85Al15 alloy, room-temperature increased from 12.1 kOe to 17.8 kOe, whereas absolute value $\Delta H_{\text{c}}/ H_{\text{c}}\Delta T$ between 27 °C 100 °C decreased 0.65%/°C 0.54%/°C. Although treatment reduces energy product magnets, reduction becomes less significant elevated temperatures, effectively disappearing 150 °C 175 °C. The microstructural effects MM-rich are analyzed in context earlier studies involving Nd(Pr)-rich alloys. As now, improved still lacks convincing, controversy-free explanation.