Preparation method of carbonyl powder

Abstract

The invention discloses a preparation method of carbonyl iron powder. The preparation method comprises the following steps of: (1) adding absolute ethyl alcohol, phosphoric acid and a coupling agent into a ball milling tank to form a mixed solution; (2) adjusting the pH value of the mixed solution to 8-9, and adding carbonyl iron powder into the ball milling tank to conduct first ball milling; (3)adding tetraethoxysilane and a coupling agent into the ball milling tank after the first ball milling is finished, adjusting the pH value of the solution to 8-9, and carrying out second ball milling;and (4) taking out the slurry after the second ball milling is finished, cleaning and drying to obtain the flaky carbonyl iron powder with the phosphate and siloxane coated structure. The flaky carbonyl iron powder disclosed by the invention not only has excellent absorption efficiency and good impedance matching performance in a low-frequency band, but also has the characteristics of low density, high temperature resistance, corrosion resistance and the like, and can meet the requirements of high-temperature, high-humidity and high-salt-mist marine climatic environments, equipment-induced multi-vibration complex environments and the like.

Description

【Technical field】 [0001] The invention relates to a powder preparation process, in particular to a carbonyl powder preparation method. 【Background technique】 [0002] With the continuous development of military stealth and anti-stealth technology, low-frequency stealth absorbing materials have been continuously developed, which has attracted key research and breakthrough directions at home and abroad. Carbonyl iron powder mainly absorbs electromagnetic waves through mechanisms such as hysteresis loss, eddy current loss, and domain wall resonance. Due to the unique onion-like structure, under the same particle size, compared with other magnetic metal powders (such as iron powder), carbonyl iron powder has low density, high magnetic permeability, high real part of magnetic permeability, and virtual The internal dispersion characteristics are good, and high absorbing performance can be achieved at low matching thickness. At the same time, it has many advantages such as low cos...

AI Technical Summary

Problems solved by technology

This method reduces the dielectric constant and increases the magnetic permeability, but the process is more complicated, and the oxidation is not easy to control, and the increase in corrosion resistance and high temperature resistance is not obvious

There is also disclosed a production method of carbonyl iron powder coated with nano-SiO2. After pretreatment, a modifier is used to change the surface polarity of SiO2 or carbonyl iron powder, and the SiO2 powder is coated and adsorbed on the carbonyl iron powder by physical methods. In addition, the process is simple, the production efficiency is high, and the dielectric constant can be reduced at the same time, but the single coating layer cannot meet the use effect in complex environments

Also disclosed is an in-situ reaction preparation method of corrosion-resistant high-permeability insulating metal powder, adding carbonyl iron powder to the in-situ reaction solution for reaction, filtering, washing, heat treatment, and cooling to room temperature to obtain the product; The surface of the soft magnetic metal composite powder prepared by this method is evenly coated with a passivation film, which has strong bonding force, high magnetic permeability and good corrosion resistance, but the method is too complicated and not suitable for mass production

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