Effect of TiC addition on microstructure and magnetic properties For MRE_2(Fe,Co)_(14)B melt-spun ribbons (MRE=Nd+Y+Dy)

摘要

Effects of a TiC addition on microstructure and magnetic properties in [MRE_(2.2)Fe_(14)B]_((100-2X))/17 2 +Ti_xC_x(MRE=Nd+Y+Dy,x=l-5) ribbons, melt spun at a wheel speed of 16 m/s, were systematically studied. X-ray diffraction and differential thermal analysis data revealed that the addition of TiC improves the glass formability in the mixed rare earth alloys without Co, resulting in partially amorphous alloys. TEM observations showed that the average grain size in the as spun samples decreases from 200 to 20 nm with increasing x from 1 to 5, confirming that the addition of TiC can significantly improve microstructure. For an optimized [MKE_2(Fe,Co)_(14)B]_((100-2x))/17 2 +Ti_xC_x sample with x=2, spun at 25 m/s and annealed at 750 deg C for 15 min, the room-temperature magnetic properties of H_(cj) =11.8 kOe, M_r=7.2 kGs, and (BH)_(max)=11.3 MGOe were obtained. Temperature coefficients for M_r and H_(cj) of -0.06 and -0.37 percent/ deg C, respectively, also were measured in the temperature range of 27-100 deg C. The new magnet alloy exhibits more uniform magnetic properties and a usable energy product to nearly 300 deg C.