Dans les industries de fabrication de haute précision telles que les semi-conducteurs, l'emballage électronique, les nouvelles énergies, l'impression 3D et le vide revêtement, high-purity aluminum powder is playing an increasingly critical role.
As industries demand higher conductivity, film-forming ability, and material purity, traditional “industrial aluminum fines” can no longer meet these stringent requirements — giving rise to high-purity aluminum powder.
Definition of High-Purity Aluminum Powder
High-Purity Aluminum Powder (HPA) refers to a fine metallic powder with aluminum content of ≥99.9% (3N and above), featuring extremely low impurity and gas content. It usually appears as spherical or near-spherical particles ranging from 10–150 μm, with some products reaching the nanometer scale.
Unlike ordinary industrial aluminum powder, high-purity aluminum powder emphasizes three key factors:
- High Purity: Impurities such as Fe, Si, Cu, and Zn are strictly controlled at the ppm level.
- Low Oxygen Content: Typically below 300 ppm, minimizing oxide layer formation.
- Batch Stability: Essential for electronic-grade materials, ensuring consistency and traceability.
Pureté Classification: Understanding the “N” Value
In high-purity materials, purity levels are denoted by the number of “N”s (e.g., 3N = 99.9%).
| Grade | Purity (%) | Total Impurities (ppm) | Typical Applications |
|---|---|---|---|
| 3N | 99.9% | ≤1000 ppm | General electronic thermal management, powder metallurgy |
| 4N | 99.99% | ≤100 ppm | Conductive paste, electronic components |
| 5N | 99.999% | ≤10 ppm | Semiconductor packaging, sputtering targets, optoelectronics |
Note: Not all materials labeled as 4N or 5N meet true standards—precise testing and process control are the keys.
Préparation Méthodes
1. Gas Atomization (VIGA/VAGE)
Molten aluminum is atomized under high-pressure argon or nitrogen, producing spherical powder.
- Caractéristiques: Excellent sphericity, high flowability, controllable oxygen content.
- Applications : Ideal for 3D printing and metal injection molding (MIM).
2. Physical Vapor Deposition (PVD)
Under vacuum, aluminum is evaporated or plasma-deposited into nano- or submicron-sized powder.
- Caractéristiques: Ultra-high purity (5N+), fine la taille des particules, high cost, limited scale.
- Applications : Mainly for research and advanced functional materials.
3. Chimique Reduction Method
Aluminum salts are reduced using hydrogen or alcoholates to produce fine metallic aluminum powder.
- Applications : Suitable for small-scale custom production.
Classification by Particle Morphology
| Taper | Description | Application |
|---|---|---|
| Spherical Aluminum Powder | Uniform particle size, excellent flowability, high packing density | 3D printing, powder metallurgy |
| Irregular Aluminum Powder | Large surface area, easy sintering | Conductive coatings, electronic pastes |
| Nano Aluminum Powder | Extremely fine (<100 nm), highly reactive | Aerospace propellants, detonating materials |
Main Application Fields
| Industrie | Function | Recommended Purity |
|---|---|---|
| Semiconductor | Sputtering targets, wafer packaging | 5N |
| Electronic Packaging | Conductive paste, thermal interface materials | 4N |
| New Energy | PV backsheet, hydrogen coatings | 4N |
| Powder Metallurgy | Aluminum-based components, MIM parts | 3N |
| 3D Printing | Additive manufacturing aluminum alloys | 3N / 4N |
Difference Between High-Purity and Ordinary Aluminum Powder
Beyond purity, high-purity aluminum powder focuses on impurity type control, oxygen content, particle size distribution, and surface state.
Ordinary aluminum powder, used mainly in coatings or construction materials, is not suitable for precision electronic applications.
Conclusion
Poudre épique provide advanced air classification mill systems and integrated process solutions tailored for high-purity and ultrafine metallic powders. Our precise air classification technology ensures uniform particle size, narrow distribution, and contamination-free processing — delivering consistent, high-quality aluminum powder for semiconductor, energy, and additive manufacturing industries. Epic Powder — Precision Grinding and Classification for High-Purity Aluminum Powder.