Method for improving corrosion resistance of neodymium-iron-boron materials by low-temperature oxidation and/or nitridation treatment

A method for improving corrosion resistance of neodymium-iron-boron (NdFeB) materials, consisting of:

• in-situ growing at least one selected from a group consisting of an oxide layer, a nitride layer and an oxynitride layer on a surface of a NdFeB magnet by correspondingly performing at least one of oxidation treatment and nitridation treatment of the NdFeB magnet;
• wherein the “performing at least one of the oxidation treatment and the nitridation treatment” consists of:
• providing the NdFeB magnet in a tube furnace or an atmosphere furnace;
• vacuumizing to 10−2-10−4 pascals (Pa) in the tube furnace or the atmosphere furnace;
• introducing at least one selected a group consisting of oxygen (O2), nitrogen (N2), ammonia gas (NH3) and water vapor with a flow rate in a range of 200-5000 milliliters per minute (mL/min) into the tube furnace or the atmosphere furnace;
• and
• controlling a temperature of the at least one of the oxidation treatment and the nitridation treatment in a range of 300-350 degrees Celsius (° C.) for 0.5-24 hours;
• wherein the oxide layer consists of an oxide of one or more elements from the NdFeB magnet;
• the nitride layer consists of a nitride of one or more elements from the NdFeB magnet;
• and the oxynitride layer consists of an oxynitride of one or more elements from the NdFeB magnet.