The temperature characteristic of iron-based nanocrystalline soft magnetic materials

      Iron-based nanocrystalline alloy core permeability core loss of Pcm and amplitude (including a is an important performance index of design high frequency transformer, the transformer size was determined, the higher the amplitude of magnetic conductivity (including a, transformer and the input signal is smaller; The lower core loss Pcm, the higher the efficiency of transformer. If permeability core loss Pcm and amplitude (including in the use of a stable temperature range, it can ensure the working stability of the high frequency transformer. From can be seen in table 1 and figure 1, 2, core permeability within - 55 ~ 200 ℃, with the temperature increases, a slight increase in little change; Core loss increases with temperature rise, presents the downward trend, all did not cause the deterioration of performance, this change should be caused by electronic and magnetic domain movement affected by temperature. As temperatures continue to rise, permeability is lower, higher core loss, magnetic can worsen sharply, no longer have the function of the magnetic device.

      Usually think Curie point is the highest limit of ferromagnetic materials using temperature. We can see that iron-based nanocrystalline alloy Curie temperature is 550 ℃, only lower than silicon steel, iron core and the alloy has been above 550 ℃ by 1 h crystallization heat treatment, organizational performance is quite stable, so in - 55 ~ 200 ℃ temperature range, the core of the microstructure changes may not happen, magnetic can also won't happen too big change, in a state of stable performance. If temperatures continue to rise, affect the performance of iron-based nanocrystalline alloy core will inevitably, magnetic would decline until disappear. With other materials such as enameled wire made of transformer heat temperature generally does not exceed 150 ℃, the product has been fully considered in the design of the high-frequency transformer temperature rise problem at work, therefore in iron-based nanocrystalline alloy core using temperature range to ensure stable performance in several commonly used soft magnetic alloy performance comparison (including Max/Bs 104 / T P/W metal loss 1 rho/kg - including Ω cm TC /
30 ℃ iron-based nanocrystalline alloy P0.2/20 k = 1.25 3.4, 90
550 iron base amorphous alloy 15 P1.0 1.56/1 k = 4, 140, 415 cobalt-based amorphous alloy 80 0.57 P0.5/10 k = 4, 140, 340 permalloy 1 j8518 P0.5 0.70/10 k = 45 56 400 power ferrite P0.2/20 k = 0.5 0.5 7.5 7.5 5 x 107 107 cold-rolled silicon steel 4 P1.0 47/1 k = 20
There is no question of 740, meets the requirement. Von Yi etc was studied in electronic transformer with iron-based nanocrystalline alloy core - 55 ~ 180 ℃ temperature range P0.4/10 k, 20 k, P0.3 P0.5 / / 50 k, P0.2/100 k, the change of the iron losses. Results show that the iron loss under different frequency and magnetic induction intensity of Pcm little change, performance range in the range of the requirements of the magnetic device, and meet the requirements of the technical characteristics of the military electronic products (+ / - 8%), which is consistent with our results. 4.2 iron-based   nanocrystalline magnetic powder core of powder core products are mainly used for inductors, inductance L is and effective permeability of magnetic powder core (including e is proportional to the quality factor Q is the expression of the magnetic powder core loss. As you can see, in - 55 ~ 150 ℃ temperature range, four different effective permeability (including the inductance of the sample e L changed little; Quality factor Q value increased at low temperatures, almost no change - 20 ~ 150 ℃. Stable performance of the reason the same as the above analysis, in low temperature of powder core loss is reduced, the higher quality factor Q value.

      Conclusion the rapid quenching technology of preparation of iron-based nanocrystalline alloy processing device made of a variety of core part is above 550 ℃ by 1 h crystallization heat treatment, organizational performance is quite stable. In this paper, through the test of several commonly used iron base nanocrystalline alloy core devices in - 55 ~ 150 ℃ temperature range of magnetic changes that iron-based nanocrystalline alloy core product is really good temperature stability, it can use to provide the basis for the user