High-performanceradialorientation rare-earth permanent magnetic tube and thermal-deformationforming method thereof

Abstract

The invention discloses a high-performanceradialorientation rare-earth permanent magnetic tube and a thermal-deformationforming method thereof, and belongs to the technical field of rare-earth permanent magnetic seamless tube manufacture. A raw-material component of the permanent magnetic tube is RE-(Fe,Co)-B, wherein RE is or one or more ofyttrium or lanthanide elements which are represented by Nd, and one or more other transition metal elements can be added at the same time; a horizontal loading horizontal-type rotation double-motion extrusion device of which a connecting angle alpha is greater than or equal to zero degree and smaller than or equal to 90 degrees is adopted, firstly, hot pressing is conducted on rapid-quenching magnetic powder to form a full-densityisotropousmagnet, then, horizontal positive shuntextrusion is conducted on the full-densityisotropousmagnet to form the radialorientation permanent magnetic tube, the tube length is greater than 50 mm, and the tube diameter is adjustable in a range of 0-150 mm.The horizontal extrusion technology overcomes the spatial height limit of a vertical device, the long-range rheological property improves the magnetism and microstructure uniformity of the permanent magnetic tube, the permanent magnetic tube of which the length, diameter and wall thickness can be freely adjusted in a large size range can be prepared, which is beneficial for the batch production of the radialorientation rare-earth permanent magnetic tube. Through conducting saw cutting on the permanent magnetic tube, nanometer rare-earth permanent rings, magnetic tiles and ceramic chips can be obtained.

Description

technical field [0001] The invention belongs to the technical field of rare earth permanent magnet seamless tube manufacturing, in particular to a high-performance radially oriented rare earth permanent magnet tube and a thermal deformation forming method thereof. Background technique [0002] Radially oriented rare earth permanent magnet rings have important applications in aerospace, electronic and electrical engineering, information technology and other fields of high coercivity, high remanence and high temperature coefficient applications. At present, the preparation methods of permanent magnet ring mainly include tile-shaped magnet splicing method, isotropic magnetic powder bonding method, radial orientation powder metallurgy sintering method and back hot extrusion method. But splicing the permanent magnet ring, the magnetic pole fluctuates greatly, the power factor is low, and the efficiency is not high; the magnetic performance of the bonded magnetic ring is low, and ...

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Problems solved by technology

However, due to the use of a vertical extrusion machine, limited by the height of the production space, the stroke of the hydraulic press is limited, and the length of the permanent magnet rings produced by the above method does not exceed 35mm, and due to the short rheological process, the tissue properties of different parts of the magnetic rings are very uneven. , especially the performance of both ends of the magnetic ring is very poor and needs to be cut off, which makes the production efficiency of the magnetic ring extremely low, resulting in an unnecessary increase in production costs, and it is difficult to achieve large-scale production

Japanese patent JPH01248504A has obtained anisotropic permanent magnet tube by two-step hot isostatic pressing method, but the hot isostatic pressing process needs to put alloy powder into a thin-walled forming sheath that is vacuumed, and apply anisotropic permanent magnet tube to the product at high temperature. Equal pressure, using high temperature and high pressure to sinter and densify the powder, the process is very complicated, and the magnet preparation process is very long; and the two-step hot pressing needs to be completed in different hot isostatic pressing equipment, resulting in unnecessary increase in cost; In addition, In the thermo-rheological process, only 10 μm thick anti-oxidation coating is used to cover the magnet to avoid oxidation, which puts extremely high requirements on the coating, and its preparation process is quite strict. In actual operation, the coating undergoes plastic deformation with the rheology of the magnet. The peeling with the magnet often occurs, and the anti-oxidation effect is limited, which limits the magnetic performance of the magnet; finally, the high-temperature diffusion of the coating atoms into the magnet alloy will affect the formation of the 2:14:1 alloy phase, and subsequent processing of the inner and outer surfaces is required

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