The atomized copper powder is further processed by electrolytic copper. It is a light rose red dendritic, irregularly packed, spherical or spherical powder. It is easy to oxidize in a humid air and can be dissolved in hot sulfuric acid or nitric acid. Low bulk density, good formability and long storage time. Uses: Widely used in powder metallurgy products, friction materials, conductive inks, electrical carbon products, chemical contacts, diamond products, electrical alloys and other industries. The spherical and spherical copper powder has a high bulk density. It is widely used in injection molding, welding materials, electronic materials and other industries.
Electrolytic copper plate-smelting-water (gas) atomization-vacuum drying-high temperature oxidation-crushing-reduction-crushing-classification
Smelt
During the melting of copper, the content of impurities must be controlled so that the finished powder has good fluidity and high
Conductivity.
The normal operation is to heat to 1150-1200°C in an intermediate frequency furnace or electric arc furnace. Smelting is the most important process before the atomization process. By controlling the copper smelting process, the effect of reducing the bulk density of copper powder can also be achieved.
Atomization
Industrialized production of atomized copper powder is divided into two types: gas atomization method and water atomization method. The main difference between these two methods is that the atomizing medium used is different, and the principle of making powder is the same. According to different gas media, it can be divided into air atomization and argon atomization. At the same time, supersonic atomization is used to obtain finer powder.
Production practice has proved that the effect of water atomization is better than gas atomization, and water atomization is atomized in air or inert gas.
Reduction
The reduction process is relatively simple, the reduction temperature is generally 400-600℃, and the time is 60-120min. During the atomization process, part of the oxygen is oxidized on the surface, and the other part becomes copper oxide and penetrates into the inside of the particles. To remove oxygen, the reduction temperature required is very high. Under this temperature condition, copper will naturally be sintered, which requires grinding these large amounts of sintered blocks. The newly developed water mist oxidation method can no longer need to do the reduction step, thus shortening the process and saving energy.
Antioxidant treatment
From a thermodynamic point of view, copper is unstable in the air, so it is inevitable that copper powder will be oxidized in the air, especially in a humid environment, the surface of the copper powder is easy to absorb water vapor in the air to form a water film. Moreover, due to the thick water film formed in the recesses on the surface of the particles, there is little oxygen infiltration and the oxygen concentration is low, so it becomes a micro-anode, and a micro-cathode is formed in the convex area where oxygen is easy to reach. As a result, the copper powder shows a poor concentration. The battery effect, the copper powder is gradually oxidized. After being treated with antioxidants, the surface of the copper powder is adsorbed and covered with a layer of film, which produces an anti-oxidation effect and can extend the service life. Benzotriazole (BTA), soap liquid, gelatin, and protein hydrolyzate all have good corrosion inhibition effects on water atomized copper powder.
TRUNNANO (aka. Luoyang Tongrun Nano Technology Co. Ltd.) is a trusted global chemical material supplier & manufacturer with over 12 years’ experience in providing super high quality chemicals and Nano materials. The Cu powder produced by our company has high purity, fine particle size and impurity content. Lower, please contact us if necessary.
