Due to the rise of mate prices of rare earth metals in recent years, the cost of NdFeB formulations has been on the rise. Although the rough embryo and finished product prices also have a certain degree of upside. But the relative profit margins have decreased, so that the various manufacturers in addition to praseodymium neodymium other than the active application of rare earth exploration and exploration. Currently widely used is gadolinium iron metal. The following is some of the current experience of some businesses.
First, for N-grade materials, the use of 25% gadolinium instead of praseodymium-neodymium in the N30-N33 product resulted in a significant reduction in formulation costs.
Specific process: formula PrNd: 23.8, Gd: 10.2, B: 1.15, Al: 1.0, Cu: 0.15, Fe surplus. Add 30% slice scrap. Using 25 mm flat slab, air milling powder control 100-200PPM oxygen, particle size 4.6-5.0 microns, 1120-1130 / 2.5h sintering, 520-540 / 3.5h aging. Available properties Br11.3-11.8KGS, Hcj> 12.0Koe, Hk> 90%.
In the N35-N38 product, 15-20% gadolinium is used to replace praseodymium neodymium.
Specific process: formula PrNd: 26.0, Gd: 6.75, B: 1.05, Al: 0.4, Cu: 0.15, Fe surplus. Using 25 mm flat slab, air milling powder control 80-150PPM oxygen, particle size 4.6-5.0 microns, 1120-1130 / 2.5h sintering, 520-540 / 3.5h aging. Available properties Br11.8-12.5KGS, Hcj> 12.5Koe, Hk> 95%.
In the H file can also be properly added Gd, after testing the indicators can be used to meet customer requirements.