Archive for year: 2012
The Chinese government strictly management of rare earth
Foreign Trade Division, Ministry of Commerce responsible person of the rare earth scarce non-renewable resources, and mining and processing of very serious damage to the environment. Can be based on protecting the environment and the exhaustion of resources, the Chinese government on the rare earth extraction, production and export of all aspects of management measures are implemented, in which the implementation of primary products of rare earth export quota license management. Dy alloy, terbium alloy products such as rare earth alloy, rare earth content is high, management will be integrated into the overall framework of the earth to be managed.
China has announced the first programmatic document of rare earth
China has announced the first programmatic document of rare earth, rare earth is a large-scale reorganization of enterprises
From the “opinions” content can be clearly seen that our country is systematically and seriously promote the development of rare earth industry. In order to effectively advance the pace of merger and reorganization, the state environmental access system, export management, taxation and other aspects of the policy will apply more stringent. Access in the industry “views”, said rare earth industry in China will be stricter access management, on the rare earth resources in the implementation of more stringent protective mining policy and environmental protection standards, accelerating the development and improvement of rare earth mining and production standards in product quality , process equipment, access requirements put forward in nine. While the implementation of strict environmental access system, strictly implement the “rare earth industry emission standards”, the development of rare earth industry, environmental risk assessment system. Rare earth industry in the strict access management at the same time, export management will also be further strengthened. According to “Opinions” in the strict control of the total rare earth mining and production, while, strictly control the rare earth metals, oxides, salts and rare earth ferroalloy exports of primary products, the exploration, production, consumption and export restrictions should be implemented simultaneously. Overall consideration of domestic resources and production, consumption and international market conditions, reasonably determine the total annual export quota of rare earth. Improve the allocation of export quotas, severely punish the reselling of rare earth export quota acts.
The developing trend of rare earth permanent magnet motor
China’s rich in rare earth natural resources and have the top reserves of rare earth mine in the world. Also the scientific research on rare-earth permanent magnetic(Neodymium Magnet) materials and rare earth permanent magnet motor has reached the international advanced level.
To full play the advantage of our rich rare earth resource and give more energy in reseach and the promotion of the rare earth permanent magnet( Neodymium Magnet) motor represented various of permanent motors is of great signficance for speeding up the realization of china entered the well-off society. Rare-earth permanent magnet(Neodymium Magnet) motor is developing in the direction of high-power (high-speed, high- torque), high-function and micro-size, of the prospect is very optimistic due to the continued expansion of the new varieties and the new application.In order to meet the needs, constant innovation of the rare earth permanent magnet((Neodymium Magnet) motor’s design and manufacturing process is required, and then the electromagnetic structure will be more complicated ,the calculation will be more accurate and also the more advanced manufacturing process.To solve above complex issues, we have to use multi-theory and systems engineering to optimize the design and improve the cost performance,so as to promote the further development of the study and industry of electrical motor.
The Exploration of Nd-Fe-B Permanent Magnetic Materials
In this these Nd-Fe-B permanent magnets are prepared by the means of vacuum sintering process.Otherwise the influence of different additives and texture on performance are respectively studied.The samples are prepared as the element proportion(Pr-Nd)33.5Fe64.85B1.15A10.5 by smelting and casting??pneumatic milling for powder??doping and mixing sufficiently??orientation and forming??vacuum sintering??mechanical treatment and etc.The experimental results shows:
(1)In the same progress of sintering??the coercivity of sintering magnet is firstly increased and then decreased with the increasing of AIN addition amount??whose maximum occurs in the point of 0.55%.but the remnant magnetism and magnetic energy product declined with its increasing.
(2)The addition of Cu makes the same trend of coercivity with AIN??but the maximum appears in the point of 0.3%.
(3)The maximum working temperature Tm of Nd-Fe-B has been computed by the theoretical formula and experimental parameter??through which the theoretical value of coercivity also has been compute din directly.
The crystal texture of magnetic body inevitably exists some difference by molding indifferent magnetic fields??which reflects the regular changes of mechanical properties in macro.As a result that Nd-Fe-B material belongs to the brittle material and has the high hardness??its mechanical properties may be improved by changing its crystal texture.The experimental result shows:
(1)In different magnetic fields??the intensity of x-ray diffraction peak of different crystal face perpendicular to the e-axis direction changes??in which the changes of (004)??(105)??(006) and(008) faces are obvious.
(2)The magnetic properties of Nd-Fe-B change with different orientation of samples??in which the remanence falls but the coercivity remain changeless.
(3)The hardness of sample decreases with the increasing of orientation intensity??which shows some relationship between crystal texture and mechanical properties.This paper adopt Hitachi s-3400N SEM??DGN-3 DC Magnetic Testing Instrumentation??BDX3200 XRD??HV-120 Vickers Hardness??Hv-1 Micro-hardness to test the crystal phase??magnetic properties?? orientation degree and hardness.There sults show that the addition of AIN and Cu makes different effects on the coereivity and maximum working temperature of Nd-Fe-B permanent-magnetic material.In addition the hardness and remnant magnetism of magnetic body exist some relationship with the crystal texture.
