white fused alumina (WFA) micro powder is available in spherical forms, which are categorized into two main types based on production processes and roundness, each suitable for different applications and cost considerations.
Spherical Types and Production Processes
- Near-spherical/quasi-spherical WFA micro powder: Produced via autogenous grinding shaping or jet milling. It has a moderate roundness (0.7–0.8) and low cost, which is suitable for general grinding, sandblasting, and conventional abrasive tools.
- High-roundness spherical WFA micro powder: Manufactured by plasma or flame melting. It features high roundness (≥0.9), excellent fluidity, and high packing density, but with higher cost. It is ideal for electronic packaging, precision ceramics, 3D printing, and other high-end scenarios.
- Ultra-fine spherical WFA micro powder: Prepared through chemical synthesis like sol-gel method. It has extremely high roundness and ultra-fine particle size (≤1μm), suitable for semiconductor polishing and nano-coatings, but with the highest cost.
Key Properties and Application Tips
- WFA micro powder is mainly composed of α-alumina with a purity of ≥99.0% and a Mohs hardness of 9. Spherical WFA micro powder has better fluidity and packing density, leading to improved sintering uniformity.
- For general grinding and polishing, near-spherical micro powder is a cost-effective choice. For precision manufacturing, high-roundness spherical micro powder is preferred to ensure performance. For ultra-precision applications, ultra-fine spherical micro powder is the right option to enhance surface quality.
