Flake high frequency soft magnetic micro powder fracturing along C crystal face, preparation method therefor and application thereof

Abstract

The invention relates to flake high frequency soft magnetic micro powder fracturing along C crystal face, a preparation method therefor and application thereof, belonging to the field of magnetic materials. The flake high frequency soft magnetic micro powder is characterized in that the micro powder is flake micro powder of an intermetallic compound RCo17, the C crystal face of the micro powder grain is parallel to the face of the flake, the thickness of the flake is of submicron size, the width thereof is of micron size, and the micro powder grain is of a rhombohedral structure and has strong negative magnetocrystalline anisotropy. The preparation method comprises the following steps of under argon shield, smelting rare earth metals and cobalt which are matched in proportion into a cast ingot, and performing full homogenization phasing treatment; and putting the cast ingot into an agate tank and ball milling for 0-3 hours, finally, transferring the material into a steel tank, ball milling for 2-6 hours in a mixed medium of normal heptane and dimethyl silicone oil, so as to enable the grain to directionally fracture along the C face into flake micro powder, wherein in ball milling, the mass ratio of medium to material is (20-40):1. The C face of the material of the invention and the face of the micron flake are parallel, so that in preparation of an oriented compound material, both rotation orientation in a magnetic field and rolling orientation through external stressing are available, and the magnetic conductivity of the compound material can be improved.

Description

technical field [0001] The invention belongs to the field of magnetic materials, and in particular relates to a flaky high-frequency soft magnetic micropowder fractured along a C crystal plane and its preparation and application. Background technique [0002] The rapid development of computer technology and information technology promotes the development of soft magnetic materials and their devices to higher frequency bands. At present, whether it is a high-performance new inductive device or an electromagnetic wave absorber related to electromagnetic compatibility and national security, such as anti-electromagnetic interference and stealth, there is a very strong demand for soft magnetic materials that can work in the GHz frequency band. The bigger it is, and the performance requirements are constantly increasing: it is hoped that it still has high microwave permeability under the premise of higher cut-off frequency. The widely used material is the easy-faced Co 2 Z ferri...

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Problems solved by technology

The widely used material is the easy-faced Co 2 Z ferrite material, due to the low out-of-plane anisotropy field and low saturation magnetization, the material not only has a low cut-off frequency, but also has a low permeability in the GHz band (Journal of AppliedPhysics, 97, (2005), 013905); Journal of Applied Physics, 107, (2010), 09A958, IEEE Transactions on Magnetics, 49, (2013), 986 and Chinese patent CN101226801, CN101065009A reported flake iron-based metal soft magnetic materials, Although its high saturation magnetization improves the magnetic permeability of the material, the limit of its out-of-plane anisotropy field is equal to the demagnetization field, resulting in a low cut-off frequency of only 2-4 GHz; Chinese Physics Letter, 25, (2008) , 1068., Patents CN101707108B and CN101699577B reported that the easy-to-surface type rare earth soft magnetic materials have a high out-of-plane anisotropy field, which is expected to greatly increase the cut-off frequency, but the reported micropowder is irregular particles, and the size is on the order of microns. The eddy current is serious in the GHz frequency band. In addition, the demagnetization effect inside the particles caused by the irregular shape makes the magnetic permeability not high.

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