AF-P Series
AF-P polishing aluminas are calcined alumina powders engineered for precision surface finishing. Each grade is designed for a specific stage of the multi-step polishing process: stock removal (cut) followed by buffing/lapping (polish). During polishing, alumina agglomerates break down into primary crystals that deliver consistent cutting action, then continue as fine smoothing agents. The balance of cut and polish is tuned by controlling calcination degree, primary crystal size, and agglomerate strength. All grades feature well-defined top cut, stable particle size distribution, and contamination-free quality.
| Parameter | AF-P-1 | AF-P-2 | AF-P-3 | AF-P-4 |
|---|---|---|---|---|
| Grade type | Ultra-Finishing | Standard Polishing | Medium Cut | Heavy Cut |
| Alpha-Al₂O₃ | ~70% | >97% | >97% | >97% |
| Na₂O | 0.35% | 0.35% | 0.04% | 0.25% |
| SiO₂ | ≤ 0.08% | ≤ 0.08% | ≤ 0.05% | ≤ 0.08% |
| Fe₂O₃ | ≤ 0.05% | ≤ 0.05% | ≤ 0.04% | ≤ 0.05% |
| CaO | ≤ 0.05% | ≤ 0.05% | ≤ 0.04% | ≤ 0.05% |
AF-P-1 is a low-calcined transitional alumina with ~70% alpha content. AF-P-2/3/4 are fully calcined with alpha >97%.
| Parameter | Unit | AF-P-1 | AF-P-2 | AF-P-3 | AF-P-4 |
|---|---|---|---|---|---|
| D50 | μm | 3.5 | 4 | 15 | 65 |
| Top cut | μm | 20 | 32 | 90 | 200 |
| BET | m²/g | 12 | 0.9 | 1.2 | 0.4 |
| Primary crystal | μm | <0.4 | 2.5 | 1.5 | 3.2 |
| Oil absorption | ml/100g | 38 | 22 | 34 | 50 |
| Bulk density | g/cm³ | 0.60 | 0.75 | 0.70 | 0.80 |
Particle size measured by laser diffraction (Malvern Mastersizer). Top cut represents D97. All values are typical.
Cut is the ability to remove stock from the workpiece. Polish is the ability to produce a smooth, glossy surface finish. These are opposing properties — higher calcination (more alpha) yields larger primary crystals and higher cut, while lower calcination yields finer crystals and higher polish. Values on a relative 1–10 scale.
| Property | AF-P-1 | AF-P-2 | AF-P-3 | AF-P-4 |
|---|---|---|---|---|
| Cut | 1 | 5 | 3 | 8.5 |
| Polish | 9 | 4 | 7 | 2 |
| Recommended stage | Finishing / mirror | Pre-polish + polish | Polish + finish | Pre-polish / stock removal |
| Agglomerate type | Soft | Medium hard | Medium hard | Hard |
| Stage | Recommended Grade | Goal |
|---|---|---|
| 1. Pre-polish (stock removal) | AF-P-4 | Remove surface defects, scratches, and oxidation at maximum rate |
| 2. Intermediate polish | AF-P-2 or AF-P-3 | Reduce roughness left by pre-polish; prepare for finishing |
| 3. Finishing (high gloss) | AF-P-1 | Produce mirror finish; minimal stock removal |
| Workpiece Material | Recommended Grades |
|---|---|
| Steel, stainless steel | AF-P-2, AF-P-3, AF-P-4 |
| Chrome, hard chrome | AF-P-2, AF-P-3 |
| Brass, copper, non-ferrous | AF-P-1, AF-P-3 |
| Precious metals, jewellery | AF-P-1 |
| Aluminium | AF-P-1, AF-P-3 |
| Stone, marble, granite | AF-P-1, AF-P-2 |
| Glass, optical glass | AF-P-1 |
| Plastics | AF-P-1 |
| Varnishes, clear coats | AF-P-1 |
| Automotive rubbing compounds | AF-P-1 |
AF-P polishing aluminas can be applied in all standard formats:
Non-hazardous under REACH and OSHA HCS. As with all fine particulates, avoid dust inhalation — use local exhaust ventilation and respiratory protection (NIOSH N95 or equivalent) when handling grades AF-P-1 and AF-P-2. Prolonged inhalation of fine alumina dust may cause mild respiratory irritation. Avoid eye contact; wear safety glasses. Full SDS available on request.