Effects of Ti and C Additions on the Microstructures and Magnetic Properties of Nd_(9.4)Pr_(0.6)Fe_(bal)Co_6B_6Ga_(0.5) Melt-Spun Ribbons

摘要

The effect of Ti and C additions on the microstructures and the magnetic properties of Nd-Fe-B isotropic nanocomposite processed from Nd_(9.4)Pr_(0.6)Fe_(bal)Co_6B_6Ga_(0.5)Ti_xC_x (x = 0, 3, 6) alloys has been investigated. As-spun ribbons were examined by using X-ray diffractometry (XRD) and differential scanning calorimetry (DSC). The results show that Ti and C additions enhance the glass forming ability and increase the crystallization temperature. XRD results of annealed ribbons indicate that Ti and C react to form TiC. The grain size was substantially refined by the addition of Ti due to the formation of Ti-enriched amorphous grain boundaries. The XRD and Atomic force microscope (AFM) technique results confirm that grains are in the size of less than 70 nm. Further addition of C enhanced the enrichment of Ti in the grain boundary phase, which led to the increase of the coercivity and the maximum energy product.