How to distinguish between nanocrystals and amorphous?
Comparison of amorphous and nanocrystalline alloys
Iron based amorphous alloys are competing with silicon steel in the field of power frequency and intermediate frequency. Compared with silicon steel, ferrous amorphous alloy has the following advantages and disadvantages.
1) The saturation magnetic flux density Bs of Fe-based amorphous alloy is lower than that of silicon steel
However, under the same Bm, the loss of iron based amorphous alloy is smaller than that of 0.23mm thick 3% silicon steel. It is generally believed that the reason for the small loss is the thin thickness of the iron based amorphous alloy strip and the high resistivity. This is only one aspect, the more important reason is that the ferro-based amorphous alloy is amorphous, the atomic arrangement is random, there is no magnetic crystal anisotropy caused by the directional arrangement of atoms, and there is no grain boundary that produces local deformation and composition migration. Therefore, the energy barriers that hinder the movement of the domain wall and the rotation of the magnetic moment are very small, and have unprecedented soft magnetism, so the permeability is high, the coercivity is small, and the loss is low.
2) The filling coefficient of the ferro-based amorphous alloy core is 0.84 ~ 0.86
3) Working magnetic flux density of ferro-based amorphous alloy core
1.35T ~ 1.40T, silicon steel is 1.6T ~ 1.7T. The weight of the iron-based amorphous alloy power frequency transformer is about 130% of the weight of the silicon steel power frequency transformer. However, even if the weight is heavy, for the same capacity of the power frequency transformer, the loss of the magnetic core using iron-based amorphous alloy is 70% to 80% lower than that using silicon steel.
4) Taking into account loss, the total valuation is 89%
Assume that the load loss (copper loss) of the power frequency transformer is the same, and the load rate is 50%. Then, to make the iron loss of the silicon steel power frequency transformer and the same as that of the iron-based amorphous alloy power frequency transformer, the weight of the silicon steel transformer is 1. Eight times. Therefore, the domestic general people agree to put aside the loss level of the transformer, generally talk about the weight, cost and price of iron based amorphous alloy power frequency transformer, is 130% to 150% of the silicon steel power frequency transformer, does not meet the market requirements of the price-performance principle. Two comparison methods are proposed abroad, one is to calculate the weight and price of copper and iron materials used in two power frequency transformers under the same loss condition, and compare. Another method is to reduce the loss of iron based amorphous alloy power frequency transformer wattage, converted into money to compensate. No load loss per watt is equivalent to 5 to 11 US dollars, equivalent to 42 to 92 yuan. The load loss per watt is equivalent to 0.7 to 1.0 US dollars, which is equivalent to 6 to 8.3 yuan. For example, a 50Hz, 5kVA single-phase transformer with silicon steel core, the price is 1700 yuan/unit; No-load loss of 28W, according to 60 yuan /W, is 1680 yuan; Load loss 110W, according to 8 yuan /W, is 880 yuan; Then, the total evaluation is 4260 yuan/set. With iron based amorphous alloy core, the price is 2500 yuan/set; No-load loss of 6W, converted into 360 yuan; The load loss is 110W, which is converted to RMB 880 yuan, and the total evaluation is 3740 yuan/unit. If the loss is not considered, the single calculation of the quotation, 5kVA iron based amorphous alloy power frequency transformer is 147% of the silicon steel power frequency transformer. If loss is taken into account, the total estimate is 89%.
5) The resistance of iron based amorphous alloy to power waveform distortion is stronger than that of silicon steel
Now testing the core material loss of power frequency transformer is carried out under the sine wave voltage with less than 2% distortion. The actual power frequency network distortion is 5%. In this case, the loss of iron based amorphous alloy increases to 106%, and the loss of silicon steel increases to 123%. If the high order harmonics are large and the distortion is 75% (such as power frequency rectifier transformer), the loss of iron based amorphous alloy increases to 160%, and the loss of silicon steel increases to more than 300%. It shows that the resistance of ferro-based amorphous alloy to power waveform distortion is stronger than that of silicon steel.
6) The ferro-based amorphous alloy has a large magnetostrictive coefficient
It is 3-5 times that of silicon steel. Therefore, the noise of the iron-based amorphous alloy power frequency transformer is 120% of the noise of the silicon steel power frequency transformer, which is 3 to 5dB larger.
7) The price of iron based amorphous alloy strip is 150% of 0.23mm3% oriented silicon steel
On the current market, it is about 40% of 0.15mm3% oriented silicon steel (after special treatment).
8) The annealing temperature of iron based amorphous alloy is lower than that of silicon steel
The annealing temperature of iron-based amorphous alloy is lower than that of silicon steel, and the energy consumption is small, and the iron-based amorphous alloy core is generally manufactured by a special manufacturer. Silicon steel magnetic cores are generally manufactured by transformer manufacturers. According to the above comparison, as long as a certain production scale is reached, iron-based amorphous alloys will replace part of the silicon steel market in electronic transformers in the power frequency range. In the mid-frequency range of 400Hz to 10kHz, even if there are new silicon steel varieties, iron based amorphous alloys will still replace most of the silicon steel market with thickness below 0.15mm. It is worth noting that Japan is vigorously developing FeMB amorphous alloy and nancrystalline alloy, its Bs can reach 1.7 ~ 1.8T, and the loss is less than 50% of the existing FeSiB amorphous alloy, if used for power frequency electronic transformers, the working magnetic flux density reaches more than 1.5T, and the loss is only 10% ~ 15% of the silicon steel power frequency transformer. Will be a more powerful competitor of silicon steel power frequency transformer. Japan is expected in 2005 to be FeMB amorphous alloy power frequency transformer trial production success, and put into production.
Amorphous nanocrystalline alloys are competing with soft magnetic ferrites in the field of middle and high frequency. In 10kHz to 50kHz electronic transformers, the working magnetic flux density of iron based nanocrystalline alloy can reach 0.5T, and the loss of P0.5/20k is less than 25W/kg, so it has obvious advantages in high-power electronic transformers. In 50kHz to 100kHz electronic transformers, the loss of iron-based nanocrystalline alloy P0.2/100k is 30 ~ 75W/kg, and iron-based amorphous alloy P0.2/100k is 30W/kg, which can replace part of the ferrite market.
Post time: Oct-13-2023