PACE Technologies ALD-0103-01E 0.30 um Deagglomerated Alumina Powder for Electronic and Soft Materials (1 lb)

Selecting the right final polishing abrasive is critical for achieving a flawless, mirror-like surface in metallography. Among the most widely used polishing agents are alumina powders and suspensions, valued for their high hardness, durability, and versatility across a range of materials.

Calcined alumina is a traditional choice, offering cost-effectiveness and availability. However, its tendency to agglomerate-especially at submicron sizes-can lead to random scratches, particularly on soft metals like aluminum, copper, and zinc. Fused and levigated alumina types vary in particle shape and purity, with fused particles being blockier and levigated forms offering more controlled sizing.

For superior results, nanometer polycrystalline alumina is the preferred option. Engineered from the harder alpha phase (Mohs 9), it delivers a tighter particle size distribution (<0.5 µm agglomerates), reduces surface defects, and provides faster material removal. Its performance is especially noticeable on soft or heterogeneous materials where surface relief and random scratches must be minimized.

Best practices include pre-wetting the polishing cloth and applying alumina via a drip method. A brief water rinse (10-15 seconds) at the end of the cycle helps remove any electrostatically bound particles, ensuring a clean and consistent surface.