Patent ID: 11908600
Assignee: YANTAI DONGXING MAGNETIC MATERIALS INC.
Field: Surface technology, coating (Chemistry)
Classification: CPC H  C  B | IPC H

Claim 3:
4. A method of forming a ceramic coating on a sintered NdFeB permanent magnet, wherein a layer of a pre-ceramic slurry is sprayed on a surface of the sintered NdFeB permanent magnet, dried and cured by heat-treatment to form the ceramic coating, the method comprising the following steps:
a) Preparing of a pre-ceramic slurry including 10 to 50% polysilazane, 5 to 10% ceramic filler, 30 to 70% organic solvent, 5 to 10% adhesive, and 0 to 1% other additives;
b) Fixing the NdFeB magnet in the preparation device as defined in claim 1;
c) Transferring the pre-ceramic slurry formed in step a) to the nozzle of the preparation device through the pump body, wherein the nozzle vertically sprays the pre-ceramic slurry on a surface of the NdFeB magnet and wherein a distance between the nozzle and the NdFeB magnet is 5 to 50 mm; and
d) Drying the pre-ceramic coating on the sprayed surface of the NdFeB magnet and curing the dried pre-ceramic coating to a ceramic coating by heat-treatment.