Overview of Common Copper Powder Types and Their Application Characteristics

1. Electrolytic Copper Powder

As the powder metallurgy industry advances, the performance requirements for electrolytic copper powder have become more diverse. Its core indicators include: bulk density of 0.6–3.0 g/cm³, purity of 99.5%–99.99%, and lead content ≤ 100 ppm. Different industries have distinct needs:

Electrical carbon industry: It requires good electrical conductivity and wear resistance. Thus, electrolytic copper powder must have a large surface area, low bulk density, and excellent formability. This allows achieving efficient conductivity with less powder while enhancing wear resistance.
Powder metallurgy components/cold-pressed diamond tool industry: A suitable bulk density (as shown in relevant data) is needed. This ensures no segregation when mixed with other powders, preventing green compact cracking.
Oil-impregnated bearing industry: Uniform large pores and good fluidity are essential. Therefore, electrolytic copper powder should have high bulk density and coarse particle size to improve bearing quality.

2. Atomized Copper Powder

Atomized copper powder is produced via “double-stream atomization” — high-pressure water or high-speed gas breaks up molten copper. It is categorized into water atomization and gas atomization (including inert gas and air atomization) based on the atomizing medium. This process uses much less energy than mechanical crushing, making it simple and cost-effective. Its core characteristics and applications are as follows:

Basic performance: It costs less than electrolytic copper powder. Most particles are spherical or irregular, with high bulk density and good fluidity. However, it has poor formability and low green compact strength.
Process improvement: Low bulk density atomized copper powder (redox copper powder) can be made through “water atomization + redox”. This improves formability and allows partial replacement of electrolytic copper powder (domestic output is small). Deep redox can further reduce bulk density but consumes more energy. Thus, it is more advisable to optimize bulk density during atomization first, then combine with redox to balance cost and formability.
Core applications: Ultra-fine atomized copper powder (bulk density around 3.0 g/cm³) is favored by the industry. It has excellent fluidity, making it suitable for MIM technology (used in copper-based heat dissipation components). However, China still lags behind foreign countries in ultra-fine powder preparation processes and equipment — ultra-refinement is the main development direction. Low bulk density ultra-fine atomized copper powder is also used in solder paste materials (mixes evenly with polymer materials), while spherical atomized copper powder is widely applied in filter materials and friction materials.
Development trend: Atomized copper powder production is low-energy and low-pollution, aligning with environmental protection strategies. It will gradually replace electrolytic copper powder to become a core raw material in powder metallurgy. Optimizing atomization processes and developing high/bulk density, low-bulk density, and ultra-fine product series is of great significance.