55results about How to "Increase the maximum energy product" patented technology

The invention discloses a method for preparing sintered NdFeB with low dysprosium (Dy) content and high performance; the method comprises the following steps of: sputtering and plating the Dy element on the surface of jet mill powder by using the powder plate technology based on magnetron sputtering on the basis of preparing NdFeB powder, and then sufficiently dispersing the Dy element to micron-sized NdFeB crystal particles by dispersing the Dy element at high temperature in the sintering and tempering process, thereby achieving the effect of improving magnetic performance of the sintered NdFeB. Compared with the introduction of the Dy element in the proportioning process of the prior art, the method disclosed by the invention has the advantages: the low dysprosium content and high performance is limited in the nano-size by adopting the physical gas-phase deposition, the consumption quantity of the Dy element during the production process is controlled effectively and the preparationof sintered NdFeB with low dysprosium content and high performance is realized. Compared with the sintered NdFeB of the same components prepared by the traditional casting and powder metallurgy process, both the intrinsic coercivity and the maximum magnetic energy product of the sintered NdFeB rare-earth permanent magnetic material obtained according to the invention are improved obviously; compared with the sintered NdFeB with the same performance prepared by the traditional casting and powder metallurgy process, the dosage of the dysprosium element is reduced remarkably. The method can be widely applicable to producing and manufacturing sintered NdFeB with high performance.

The invention discloses a sintered neodymium-iron-boron magnet, comprising the following components in percent by weight: 29.5%-32.5% of R, 62.85%-67.54% of Fe, 0.96%-1.15% of B and 2.0%-3.5% of TM, wherein R consists of Nd, Pr and Gd or consists of Nd, Pr and Ho; B represents boron, Fe represents iron, and Tm is one or more in Al, Nb, Cu, Co, Ga and Zr. In addition, the invention also discloses a preparation method of the sintered neodymium-iron-boron magnet, and the sintered neodymium-iron-boron magnet is prepared by adopting a quick-curing piece technology and a forming and pre-pressing process. The invention has the advantages that the largest magnetic energy product and intrinsic coercive force of the sintered neodymium-iron-boron magnet can be furthest improved, and the produced sintered neodymium-iron-boron magnet has high residual magnetism and high coercive force and is lower in cost.

The method includes steps: (1) using ingot-casting technique to manufacture Nd-Fe-B ingot-casting alloy, or using technique of rapid hardening sheet to produce rapid hardening sheet of Nd-Fe-B alloy; (2) first carrying out coarse crushing for alloy, then producing powder through airflow grinding; (3) adding powder of boron nitride or magnesia, and mixing them evenly; (4) pressure molding oriented mixed powders under magnetic field, and then carrying out cold isopressing process for blanks; (5) sintering and tempering blanks in high vacuum sintering furnace. Nd-Fe-B magnet produced according to the invention possesses better magnetic performance and corrosion resistance than magnetic performance and corrosion resistance of magnet without adding powder of boron nitride or magnesia.

The invention provides a method for preparing a composite sintered neodymium-iron-boron permanent magnet material added with gadolinium, holmium and yttrium. The method includes the steps of primary batching, fusion casting, milling, secondary batching, powder mixing, forming, sintering and heat treatment, wherein in the primary batching step, iron alloy added with three rare earth elements of the gadolinium, the holmium and the yttrium is composited, and in the secondary batching step, oxide added with the three rare earth elements of ultrafine gadolinium, holmium and yttrium and cuprous oxide powder are composited. By the method, the relative surplus and cheap gadolinium, holmium and yttrium can be used for partially substituting for rare earth elements of neodymium, praseodymium or dysprosium, and accordingly neodymium, praseodymium or dysprosium consumption can be decreased by 10-30wt.%. Besides, Curie temperature and coercivity force of the prepared neodymium-iron-boron permanent magnet material are increased, corrosion resistance is enhanced, operating temperature and toughness are increased, and processability is improved.

The invention discloses a permanent magnet for a loudspeaker and a processing technology thereof. The permanent magnet comprises the following components by weight percentage: 10-14.5 percent of neodymium, 1.5-2.4 percent of calcium carbonate, 2.2-2.6 percent of titanium, 8-12.5 percent of zinc oxide, 2-4.5 percent of boron, 3-4.5 percent of aluminum oxide, 0.2-0.8 percent of gallium and balance of iron oxide. The raw materials are treated through oxidization, air-stream milling, molding, isostatic pressing, oil peeling, sintering and post-processing to obtain products. By using the iron oxide as the foundation bed of the permanent magnet, when the molar ratio of ferric iron to ferrous iron in the iron oxide is 2:1, the maximum magnetic energy product of the permanent magnet is the highest, the magnetic induction coercivity is high, the connection of grains in the permanent magnet is stable after long-time use, the sound quality of the loudspeaker is guaranteed, the long-time use of the loudspeaker is facilitated, different alloy metals can be added according to loudspeakers at different frequencies, the application scope is wide and the overall performance of the loudspeaker is improved.

An isostatic pressing method for shaping the adhered nano-crystalline NdFeB magnet includes such steps as proportionally mixing the nano-crystalline NdFeB magnet powder with adhesive, loading the mixture in sleeve rubber pipe, isostatic pressing under 500-800 MPa, and solidifying at 130-200 deg.C. Its advantages are high density, high magnetic performance and less consumption of adhesive.

The invention relates to a high-performance Nd-Fe-B permanent magnet material. The permanent magnet material is characterized by comprising the following constituents by weight percent: 31-35% of PrNd, 0.5-1% of Gd, 0.05-0.15% of Ga, 0.05-0.15% of Zr, 0.8-1.6% of B, 0.2-0.5% of Co, 0.1-0.4% of Al, 0.05-0.2% of Cu, 0.05-0.3% of Mo, 0.05-0.3% of Ti and 0.1-0.5% of LaCe with the balance being Fe. In the permanent magnet material, the PrNd content and the Nd content are reasonably controlled, meanwhile, elements such as rear earth and Zr are added, thus, the integral maximum magnetic energy product of a magnet is improved, the usage amount of the magnet is reduced, and the permanent magnet material is lighter and is lower in cost.

The invention belongs to the field of rare earth permanent magnet materials, and discloses a pure high-abundance rare earth Ce, La and Y-based multi-element nanocrystalline permanent magnet alloy andpreparation. The pure high-abundance rare earth Ce, La and Y-based multi-element nanocrystalline permanent magnet alloy has a composition of RE<x>Fe<101-x-y>B<y> according to an atomic ratio, x is greater than 11.5 and less than 17.5, y is greater than 5.7 and less than 6.3, and RE is [(Ce<1-a>La)<1-b>Y] composed of three rare earth elements Ce, La and Y according to a certain ratio, a is greater than 0 and less than 0.5 and b is greater than 0 and less than 0.5. The nanocrystalline permanent magnet alloy with high coercive force, high maximum magnetic energy product and excellent thermal stability is prepared by adjusting the mutual synergistic effect among high-abundance rare earth Ce, La and Y. The alloy does not contain Nd/Pr/Dy/Tb and other low-abundance rare earth, the cost performance of the magnet can be improved, and the problem of unbalanced utilization of the rare earth can be effectively solved.