磁粉温度稳定性测量装置及测量方法

THE MEASUREMENT EQUIPMENT AND METHOD OF THE TEMPERATURE STABILITY OF MAGNETIC POWDERS

我们利用冲击差值补偿法,建立了一台测量磁粉温度稳定性的装置.该装置的灵敏度为2.1×10~4/mm,测量重复性为8×10~5.我们使用该装置测量了γ-Fe_2O_3等几种磁粉在使用温度范围附近的可逆和不可逆变化.包钴和掺钴的γ-Fe_2O_3磁粉的变化规律与报道的相符.对于普通的γ-Fe_2O_3,当温度从20℃上外到80℃时,剩余磁感应强度 Br 减少了5%;在这个温度范围内经五次循环以后,剩余磁感应强度随温度的变化是可逆的,其温度系数-5×10~4/℃.

This paper builds up a set of equipment measuring the temperature stability of magnetic powders by the shock difference-compensated method. The sensitivity and the repeatability of the equipment are,respectively,2×10~(-4) and 8×10~(-5).The reciprocal and the nonreciprocal change of γ-Fe_2O_3 and other magnetic powders in the region of the used temperature are measured by the equip- ment.The changing law of the Cobalt-absorbed and the Cobalt-doped γ-Fe_2O_3 is agreement with that in other published papers.To ordinary γ-Fe_2O_3 magnetic powder,when the temperature changes from 20℃ to 80℃,the remanent magnetization Br decreases 5 percent.In above temperature region,the changing of the remanent magnetization Br is reciprocal with the temperature through five times cycling,and the temperature coefficient of γ-Fe_2O_3 is about -5×10~(-4)/℃.