Detailed explanation of key processes for preparing flake silver powder, bright silver powder, conductive ball shaped silver powder, ultrafine silver powder, flake silver coated copper powder, ball shaped silver coated copper powder, dendritic silver coated copper powder

The properties of flake silver powder are stable, and the particles are in surface or line contact, so the resistance is relatively low and the conductivity is good. Silver flakes are one of the important materials for electronic components, widely used in thin film switches, filters, carbon film potentiometers, tantalum capacitors, semiconductor chip bonding, and other electronic components.

      Flake shaped nano silver powderThe key process of preparation is ball milling. The process of ball milling is quite complex, and the quality of the microstructure, diameter to thickness ratio, and surface state of flake silver powder all depend on the ball milling process. The main influencing factors of ball milling include ball grading, ball milling speed, ball to material ratio, milling time, type and amount of grinding aid, milling atmosphere, milling temperature, and so on.

Different ball milling aids have different effects on the properties of powders. If anhydrous ethanol is used as the wet grinding medium, the silver powder particles prepared are coarser and the silver flakes are larger, but very shiny. The powder prepared by using oleic acid as the ball milling medium has good flakes and a silver gray color. The silver powder prepared using stearic acid as the ball milling medium has good flakes and a silver gray color. The silver powder prepared using composite additives has a bright gray color.

The so-called grinding aid refers to a chemical substance that can significantly improve the efficiency of crushing operations or reduce the energy consumption per unit product. It includes both organic and inorganic substances. The main purpose of adding grinding aids is to improve the grindability of the material, reduce the interaction between particles and the adhesion of fine particles on the grinding medium, provide fluidity of the material inside the mill, and thus improve the fineness and quality of the product.

There are two main perspectives on the mechanism of action of grinding aids. One is the "adsorption reduces hardness theory", which holds that the adsorption of grinding aid molecules on particles reduces the surface energy of the particles or causes dislocation migration in the near surface layer lattice, thereby reducing the strength and hardness of the particles. The second theory is the "slurry rheology regulation" theory, which holds that grinding aids reduce the viscosity of the slurry and promote particle dispersion by regulating the rheological properties of the slurry and the surface electrical properties of the mineral particles. Both theories explain the mechanism of action of grinding aids from a certain perspective, but grinding aids act on powders in a highly complex ball milling environment, so they should be considered comprehensively.

According to the experiment, the amount of ball milling aid added is closely related to the loose packing density. As the amount of ball milling aid added increases, the loose packing density of the powder continuously decreases. When the amount of ball milling aid added exceeds 1.5%, the loose packing density of the powder gradually increases again. Therefore, the amount of ball milling aid added can be considered to be controlled at around 1.5%. Hongwu Nano also supplies flake aluminum silver powder with low and normal bulk densities. Please refer to the detailed parameters in the product for more information

Nano antibacterial silver powder, conductive flake silver powder, bright silver powder, conductive spherical silver powder, ultrafine silver powder, flake silver coated copper powder, spherical silver coated copper powder, dendritic silver coated copper powder.

Submicron silver powder in the silver powder series: