Brown Fused Alumina (BFA) Micro Powder, chemically known as calcined alumina (Al₂O₃) with a typical purity range of 94.5% to 97%, is an ultra-fine, angular ceramic abrasive powder derived from the fusion of bauxite, iron filings, and coke in an electric arc furnace (at temperatures exceeding 2,000°C), followed by crushing, purification, and ultra-fine milling.
Brown Fused Alumina (BFA) Micro Powder, chemically known as calcined alumina (Al₂O₃) with a typical purity range of 94.5% to 97%, is an ultra-fine, angular ceramic abrasive powder derived from the fusion of bauxite, iron filings, and coke in an electric arc furnace (at temperatures exceeding 2,000°C), followed by crushing, purification, and ultra-fine milling. Distinguished by its deep brown to reddish-brown color (a result of iron oxide impurities, ~1.5–3.0%), this micro powder features sharp, crystalline particles with a Mohs hardness of 9.0, making it a cost-effective and versatile material for precision applications.
• Hardness & Toughness: Balanced hardness (Vickers hardness: 1,800–2,200 HV) and fracture toughness, offering excellent cutting power and resistance to chipping—superior to white fused alumina in rough and medium precision applications.
• Particle Morphology: Irregular, sharp-edged crystalline structure (alpha-Al₂O₃ phase) with high aspect ratio, ensuring strong abrasive action and uniform material removal.
• Thermal Stability: Exceptional heat resistance (melting point: 2,050°C) and thermal conductivity, suitable for high-temperature processing and applications where thermal shock resistance is critical.
• Chemical Resistance: Resistant to most acids, alkalis, and organic solvents; chemically inert at ambient and moderate temperatures, with low solubility in water.
• Density: True density of 3.95–4.0 g/cm³ and bulk density of 1.5–1.8 g/cm³, providing good packing efficiency in coatings and composites.
• Particle Size Distribution (PSD): Tightly controlled PSD with typical particle sizes ranging from 0.5 μm to 20 μm (submicron grades down to 0.1 μm available for ultra-precision use). Grades are standardized per FEPA (F400–F2500) and ANSI standards, with narrow PSD to minimize oversize particles and ensure consistency.
• Purity & Impurities: Contains trace impurities including Fe₂O₃ (1.5–3.0%), SiO₂ (0.1–0.5%), and TiO₂ (2.0–3.0%), which contribute to its brown color and enhance its toughness (compared to white fused alumina). High-purity grades with Fe₂O₃ <1.0% are available for specialized applications.
• Surface Properties: Hydrophilic surface with high surface energy, enabling good wetting and dispersion in water-based and solvent-based systems (compatible with most binders: epoxy, phenolic, acrylic).
1. Precision Polishing & Lapping: Used as a micro-abrasive in lapping pastes, slurries, and compounds for finishing hard materials (e.g., stainless steel, cast iron, glass, ceramics, and semiconductor wafers), delivering surface roughness (Ra) as low as 0.05 μm.
2. Functional Coatings: As a reinforcing additive in thermal spray coatings (HVOF, plasma spray) and anti-slip coatings for industrial machinery, automotive parts, and aerospace components—improving wear, corrosion, and skid resistance.
3. Ceramic & Refractory Composites: A critical raw material for manufacturing high-strength alumina ceramics, refractory bricks, and investment casting shells, enhancing thermal shock resistance and mechanical strength.
4. Electronic Materials: Used in the production of ceramic substrates, thick-film pastes, and polishing slurries for semiconductor wafer backgrinding and dicing, ensuring high precision and low surface defects.
5. Metalworking & Tooling: As a grain additive in grinding wheels, honing stones, and abrasive belts for precision grinding of carbon steel, alloy steel, and cast iron—ideal for removing material efficiently while maintaining dimensional accuracy.
Brown Fused Alumina (BFA) Micro Powder is non-toxic but may cause respiratory irritation or eye damage if inhaled or in contact with mucous membranes. It should be handled in a well-ventilated area with dust masks (N95/P100) and safety goggles. Store in a dry, sealed container at room temperature to prevent moisture absorption (which can cause clumping) and avoid contact with strong acids at high temperatures (may react to form aluminum salts).
This micro powder is a workhorse material in precision manufacturing, offering a superior balance of performance, cost-effectiveness, and versatility—making it the preferred choice for abrasive, coating, and composite applications across automotive, aerospace, electronics, and metalworking industries.
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