The difference between platelet aluminum oxide & white aluminum oxide
Platelet aluminum oxide & white aluminum oxide are white micropower with α-Al2O3.But there are big differences on the following items:
I. Essential differences in production processes
1.white aluminum oxide
Raw material:industrial aluminum oxide powder
Melting in an electric arc furnace at 2000–2250℃,cooling crystallized,then crush,grinding and the particles become sharped multi-faceted.
White aluminum oxide SEM picture
2,Platelet aluminum oxide
Raw material: Ultrafine calcined α-Al₂O₃
Addition of morphology control aids; Process: Low-temperature solid-state sintering at 1250–1400℃ to control the two-dimensional directional growth of crystals.It grows into thin, flaky single crystals with a large aspect ratio.
II. Key Performance Comparison
1. Grinding / Polishing
White aluminum oxide: sharp edges, strong cutting force, and high removal efficiency; polishing easily produces fine scratches, primarily used for rough grinding, heavy grinding, and sandblasting.
Platelet aluminum oxide: Planar sliding grinding, no sharp edges, no scratches on the workpiece, excellent mirror polishing effect; small cutting depth, primarily for ultra-precision polishing.
2. Filling, thermal conductivity, coating
White aluminum oxide: equiaxed particles, large packing voids, disordered thermal conductivity pathways, poor coating/filler spreading.
Platelet aluminum oxide:Thin sheets are easy to orient and lay flat, forming continuous heat conduction channels; the coating has strong barrier properties, gloss, and lubricity, making it suitable for thermally conductive adhesives, pearlescent coatings, and cosmetic fillers.
III. Differences in Application Areas
White aluminum oxide
1. Abrasives and grinding tools: grinding wheels, cutting discs, sandpaper, stainless steel sandblasting, rough grinding of hardware; high-speed steel and high-carbon steel grinding.
2. Refractory materials: corundum bricks, ladle castables, sliding nozzles, precision casting sand; high temperature wear-resistant aggregates
Platelet aluminum oxide
1. Semiconductor/Optical Precision Polishing: Silicon wafer CMP, optical glass, crystals, sapphire mirror polishing, scratch-free, high yield.
2. Thermally conductive filling materials: thermally conductive silicone grease, thermally conductive pads, epoxy potting compound, and heat-dissipating plastics, forming a continuous thermally conductive network.
3. Coatings/Pearl/Cosmetics: Increases the gloss of paint films and blocks moisture; Makeup foundation, eyeshadow (smooth coverage, pearlescent texture)
4. Special ceramics and fine refractories: ceramic toughening, low-shrinkage refractory castable fine powder, composite coating wear-resistant filler
IV. Comparison of available sizes and Corresponding D50
White aluminum oxide
| Size | D50(um) | Size | D50(um) |
| #240 | 57.0±3.0 | #1200 | 9.5±0.8 |
| #280 | 48.0±3.0 | #1500 | 8.0±0.6 |
| #320 | 40.0±2.5 | #2000 | 6.7±0.6 |
| #360 | 35.0±2.0 | #2500 | 5.5±0.5 |
| #400 | 30.0±2.0 | #3000 | 4.0±0.5 |
| #500 | 25.0±2.0 | #4000 | 3.0±0.4 |
| #600 | 20.0±1.5 | #6000 | 2.0±0.4 |
| #700 | 17.0±1.5 | #8000 | 1.2±0.3 |
| #800 | 14.0±1.0 | #10000 | 0.9±0.1 |
| #1000 | 11.5±1.0 | #30000 | 0.5±0.1 |
Platelet aluminum oxide
| Size | D0(um) | D3(um) | D50(um) | D94(um) |
| #400/A40 | <77.6 | 39-44.6 | 27.7-31.7 | 18-20 |
| #500/A35 | <64.2 | 35.4-39.8 | 23.8-27.2 | 15-17 |
| #600/A30 | <50.4 | 28.1-32.3 | 19.2-22.3 | 13.4-15.6 |
| #700/A25 | <40.1 | 24.4-28.2 | 16.1-18.7 | 9.6-11.2 |
| #800/A20 | <32.0 | 20.9-24.1 | 13.1-15.3 | 8.2-9.8 |
| #1200A15 | <25.2 | 14.8-17.2 | 9.4-11 | 5.8-6.8 |
| #1500/A12 | <20.3 | 11.8-13.8 | 7.6-8.8 | 4.5-5.3 |
| #2000/A9 | <16.3 | 8.9-10.5 | 5.9-6.9 | 3.3-3.9 |
| #3000/A5 | <12.5 | 6.6-7.8 | 4.3-5.1 | 2.55-3.05 |
| #4000/A3 | <10.0 | 4.8-5.6 | 2.8-3.4 | 1.5-2.1 |
V. Conclusion
1. White aluminum oxide = electrofused sharp-angle abrasive: mainly used for high-power cutting, sandblasting, and high-temperature refractory aggregate, pursuing high removal rate and high wear resistance
2. Platelet aluminum oxide = sintered sheet functional powder: mainly used for mirror polishing, thermal conductivity filling, coating and makeup, achieving low scratch, high gloss and high thermal conductivity through flat sheet structure.