Ferrite magnets manufacturing process of the core features, appearance quality, cost, delivery, etc. with different implications. A result of business process equipment and processes that match the status of the situation vary, but it is pointed out that the whole ferrite Health
Production and operation of the key issues. Technical quality control is for the production and business services, and therefore is bound to knot
All of these practical issues work.

1 raw material selection and formulation

To improve one of the key characteristics of soft ferrite in the formula (including the second milling miscellaneous and Canada) and therefore should focus on options Good Lord formula expected, the main formula required a higher purity material containing harmful impurities such as chlorine roots, acid radical such as less chemical activity and better mobility, particle size distribution appropriate, three kinds of material than the surface area of the main formula better match. The power of Iron Oxygen body for manufacturers at home and abroad about the recipe: Fe203 (53 ~ 54) mol ~ A), MnO (35 ~40) m01%, ZnO (8 ~ 12) m01% between. Such as PC44, a formula for the manufacturers to take: Fe203 53.3m01%, Mn0 36.5m01%,, Zn010.2mol%. To promote solid-state reaction, flux, prevent grain growth,To improve the material properties and increase the mechanical strength, etc., usually in the formula, we should add some useful impurities, such as the A1203, HfO3, NbO205, TiO2, V2O5, Cr2O3, CaO, ZrO, Pb3O4 and CoO, etc., but to control a good tim Amount, too much but harmful. In this process, should focus on prevention and control of the purity of raw materials and to ensure the formula that the amount of accuracy.
2 get the materials ready
Typical oxide stock preparation (wet mixture) process, for example, that process included a sand (or ball)
Grinding, a spray-dried, pre-burn, the second ball (or sand) milling, secondary procedures such as spray-drying. A sand (or the ball) The main purpose of grinding is to ensure that the main formula feed mixing uniformity, from the perspective of production efficiency, generally opt for sanding method
Time in about lh can (you need to 6h milling around), material: ball: water = 1:2 ~ 2.5: O. 6 ~ O. 7, Using diameter steel balls. The purpose of a spray drying the raw material is mixed evenly drying, granulation, it have a certain density, which is conducive to the conduct of solid-state reaction and improve the efficiency of pre-burn,

3 Forming
Molding is a soft ferrite manufacturing process, one of the key processes, dry pressing is often used in
Molding methods. Shaping the quality of the core geometric size, appearance, have a great impact on the electromagnetic properties. Forming
Blank pieces of uniform density is particularly important, blank pieces of uniform density would lead to cracking of sintered products appear, from layer
, Deformation and other defects, which is common in pot-shaped, high degree of high-arm thin EC, EEL-shaped core in the other. Forming a
To control the volume, one of the most difficult process, its particle size material, mobility, adhesion, mold tools, presses, as well as commissioning, operators of the requirements are higher. Press improper operation, use the pellet feature is not good, or mold design is not in place, will result in uneven product micro-structure, internal cracks. Granules determines the mobility of particle material in the mold cavity fill rate and fill effects; mold should be designed to root
According to product shape, blank pieces of contraction ratio, pellet loading ratio may be forming, etc., overall consideration to its suppression of side, the relevant size, cavity height, the die taper off billet.
In this process, should focus on prevention and control of the different characteristics of the selection and use of pellet feed, Green weight, Core at the end of the uniformity of thickness and density, prevent internal cracking, or starting a batch into the next layer of products on the order.
4 Firing
Firing directly determines the final composition of ferrite, phase distribution, grain size, compactness,Size, appearance and performance. Firing should be based on equipment used for sintering, pre-burn temperature high and low, pre-burn materials contractility, Adhesive types and join the ratio of product performance requirements, shape and size, weight and mode of loading blank square the different surface to determine the appropriate sintering temperature and sintering curve. In general, warming stage (approximately from room temperature to500 ?), mainly within the blank pieces of water, adhesives and lubricants volatilization process, this time to be slowly warming up to avoid the free blank pieces of crack; Then there was the blank pieces of a gradual contraction phase, the heating rate may be appropriate to increase, but from 900 ? to 1200?, heating rate should be appropriate, as it affects the core section of burning grain size, uniformity, porosity and distribution, etc.; to the highest sintering temperature, there should be about a 3 ~ 5h insulation segment; in cooling stage, cooling Rate and oxygen content of the electromagnetic properties of the product and the passing rate is also greatly affected.
In the firing process, should focus on prevention of product adhesion, deformation and cracking; key control oxygen content, kiln
Tail pressure changes as well as product dimensions and performance consistency. According to different requirements of customers and products,
Specification process, the implementation of Ding, set temperature, set the atmosphere, will be placed on a regular basis to clear the row of blanks methods and standardization of plastic pipes mode of operation.

5 Grinding

The firing of the core only a few can be used directly, the majority must be grinding before they can be
Must meet user requirements and mechanical dimensions and appearance. Core of the grinding processing methods usually have straight-through, disc
Cycle through the type and disc type and so on. Straight-through processing efficient, but it needs Xiadian belt, steel strip
, And the core are moving relative to the table, so the less accuracy, consistency requirements on the inductance and high
Users need to open the air gap of the core volume, the kinds of processing methods will be compromised. Cycle using disc-type grinder plus
Working hours, due to relatively fixed core and the table and does not pad any medium, so a higher machining accuracy, suitable for
Processing of a small core, the core defect is wear and tear (off blocks) will be more serious cases.
To improve product quality and consistency of grinding, to selected strip, belt, if necessary, in accordance with product
The grinding characteristics, production of some special fixtures can be a good way to ensure the consistency of batch grinding. In addition, the magnetic
Core on the adhesion of foreign matter, such as sintered corundum sand, feed powder, such as the handling of burr is also important to remove will not clean
Product grinding ramp leading to the surface is not smooth, size deviation large, inductance and power loss of relatively large gap between casual and so bad after fruit, so before processing, the core simple sorting and processing is also very necessary. This process should be re -
Point operator tendency to prevent processing errors, focus on standardizing and grinding feed speed, grinding plus different products
Industrial equipment selection and processing methods to ensure product sizes and inductance parameters.