Method for preparing hollow magnetic ball

Abstract

The invention relates to a method for preparing a hollow magnetic ball (tube) of metal and alloy, which belongs to the field of magnetic material preparation, in particular to the preparation of lightmagnetic particles. The method comprises the following steps of: adopting metallic iron particles as a template, depositing or plating a layer of metal cobalt, nickel or an alloy layer of the metal cobalt and the nickel on the surface thereof for preparing a 'core-shell' composite structure, and then using the reaction of primary cell to melt the iron core for further obtaining the hollow magnetic ball of the metal cobalt, nickel and the alloy. As the metallic iron particles are taken as the template, surface sensitizing processing is not needed to be implemented to the template, thereby simplifying the preparation process; and simultaneously, by controlling the size of the iron core, the size of the hollow ball can be controlled. When a linear or chain-shaped iron core is taken as the template, tubes of the metal cobalt, nickel and the alloy thereof can also be prepared. The hollow magnetic ball prepared by adopting the process is characterized by low density and high specific saturation magnetization strength, and can be used as magnetorheological intelligent material and military stealth material.

Description

technical field [0001] The invention relates to a method for preparing a magnetic hollow sphere (tube), which belongs to the field of magnetic material preparation, in particular to the preparation of light magnetic particles. Background technique [0002] With the rapid development of material science and technology, the types of magnetic materials are increasing day by day, and their functions are also expanding. They have bright application prospects in fields such as new intelligent magnetorheological materials, medical targeted drug carriers, and stealth materials. However, traditional magnetic materials have a high density, which limits their application in some fields. For example, in magnetorheological fluids, the density of magnetic particles is high, which leads to poor sedimentation stability in the carrier liquid, thus affecting the magnetic field. The performance of the rheological fluid may even fail completely; similarly, in the research of military stealth ai...

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Problems solved by technology

[0004] However, when organic polymer particles are used as the template of the core-shell composite structure to prepare the hollow microspheres of the magnetic shell, the commonly used magnetic materials are generally inorganic materials such as iron, cobalt, nickel and other metal elements, alloys or their oxides, etc. It becomes difficult to directly deposit or plate magnetic metal or alloy shells on the surface of organic polymer materials. It must be activated and sensitized, which increases the complexity of the preparation process. At the same time, it uses pyrolysis to remove polymer templates. , only metal oxide magnetic shells can be obtained, which reduces the specific saturation magnetization of magnetic hollow particles to some extent

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