Permanent magnetic ferrite (
(SrO) SrO or BaO and Fe2O3 as raw material, through the ceramic technology (
Pre burn, crushing, milling, pressing molding, sintering and grinding)
Made with wide hysteresis loop, high coercive force, high remanence, once magnetization can keep constant magnetic functional materials.
According to the different production technology, permanent magnet ferrite can be divided into sintered and bonded two kinds, including sintering is divided into dry pressure molding and wet forming, bonding are divided into extrusion molding, pressure molding and injection molding.
By bonding and synthetic rubber compound made of soft ferrite powder with softness, elasticity and distortion and called the rubber magnets.
According to whether time molding plus magnetic field is divided into isotropic and anisotropic permanent magnet permanent magnet current age is the electronic age, no permanent magnetic ferrite magnet, there is no electronic industry, permanent magnet ferrite as a basic function of the electronics industry material, has penetrated into every field of human life and production.
In automobile, motorcycle, TV, acoustics, computer and communication terminals, medical instruments, etc, to obtain the widespread application, it is an important aspect of energy development.
No matter from the perspective of resources, or from the point of view of energy, and application, permanent magnet ferrite development prospects are very broad, its demand is growing.
4 1995 permanent magnetic ferrite demand in our country.
50000 tons (
50000 tons under-burnt clinker)
The demand for 6-1997
70000 tons (
Pre under-burnt clinker - 7
Demand in 2000, 150000 tons (
Pre under-burnt clinker 180000 tons)
Weaving & throughout;
Period, total permanent magnetic ferrite production in China has gradually replace & other;
Kingdom of permanent magnet & throughout;
Japan, ranking the first place.
The preparation method of permanent magnet ferrite powder.
At present, the preparation of permanent magnetic ferrite is varied, but basically has the following several ways: (
Chemical coprecipitation method (
Molten salt method (
Vitrification crystallization (
Hydrothermal synthesis method,
Sol & ndash;
Gel method (
Organic resin method (
Self-propagating high temperature synthesis method.
Permanent magnetic ferrite of new technology and new technology to improve the performance of permanent magnet ferrite way: (
Improve the orientation degree (
Improve the sintering density (
Improve the ferrite M phase of Mn & amp;
Refine grain and improve the effect of granular rate (
Control the ferrite grain size uniform a sintered body.
Permanent magnetic ferrite is one of the largest output in the current permanent magnet materials.
Since the advent of permanent magnetic ferrite materials, technical performance, continuously improve products keeps increasing, the manufacturing process continuously improve, use equipment constantly updated, application scope expands unceasingly, so the social benefit and economic benefit are increasing.
Abroad due to the raw materials, such as lack of labor and environmental restrictions, no longer for these products raw materials production, and therefore is transferred to the third world.
At present, some large and medium-sized factories in China, the use of its abundant funds and technical advantages and key production equipment from abroad and domestic version with domestic auxiliary equipment to form a complete set of advanced production lines.
Some township enterprises and individual enterprises, using technology and science and technology, the use of the traditional equipment and cheap human resources.