How to make demagnetization testing resistant to high-temperature

The principle of high-temperature demagnetization of neodymium iron boron magnets is as follows: when the neodymium iron boron magnets are heated to a temperature above the Curie point, the molecules in the magnets start to vibrate vigorously, resulting in a decrease in the magnetization of the magnets. If the temperature continues to rise, the magnetization of the magnets will continue to decrease until it reaches a point where the magnets become completely demagnetized. This process is irreversible, meaning that once the magnets are demagnetized, they cannot be restored to their original magnetization level.

In summary, the high-temperature demagnetization of neodymium iron boron magnets is a process in which the magnetization of the magnets decreases as the temperature increases above the Curie point. This process is irreversible and can result in the complete demagnetization of the magnets.

The testing method and steps for the demagnetization of neodymium iron boron magnets at high temperatures, as well as the specific requirements, are described in detail as follows:

1. Prepare testing equipment and samples: A high-temperature oven, a magnetic measuring instrument, and several neodymium iron boron magnets to be tested are required.

2. Record the initial magnetization: At room temperature, measure the initial magnetization of each neodymium iron boron magnet to be tested using a magnetic measuring instrument and record it.

3. Carry out high-temperature treatment: Place the neodymium iron boron magnets to be tested in a high-temperature oven and heat them according to the预定 temperature and time. Usually, the temperature range is 200℃ to 300℃, and the time is 1 hour to 2 hours.

4. Measure the magnetization after demagnetization: After the high-temperature treatment is complete, remove the neodymium iron boron magnets from the oven and allow them to cool to room temperature naturally. Then, measure the magnetization of each neodymium iron boron magnet again using a magnetic measuring instrument.

5. Calculate the demagnetization rate: Calculate the demagnetization rate of each neodymium iron boron magnet according to the initial magnetization and the magnetization after demagnetization. The demagnetization rate can be calculated by the following formula: demagnetization rate = (initial magnetization - magnetization after demagnetization) / initial magnetization × 100%.

6. Analyze the test results: Evaluate the high-temperature stability of neodymium iron boron magnets based on the demagnetization rate.

During the high-temperature demagnetization test of neodymium iron boron magnets, the following requirements must be met:

1. The testing environment should be kept dry and clean to avoid interference from the outside world on the magnetic measuring instrument.

2. The temperature of the high-temperature oven should be accurately controlled to avoid excessive temperature fluctuations.

3. The neodymium iron boron magnets to be tested should be kept dry and clean to avoid surface contamination or oxidation.

4. The magnetic measuring instrument should have high accuracy and sensitivity to accurately measure the magnetization of neodymium iron boron magnets.

5. During the test, neodymium iron boron magnets should be protected from impact or vibration to avoid affecting the test results.

In conclusion, the high-temperature demagnetization test of neodymium iron boron magnets is an important method to evaluate the high-temperature stability of neodymium iron boron magnets. Accurate and reliable test results can be obtained by strictly following the test method and requirements.