CORUNDUM (aluminium oxide)
The most commonly used mineral in the production of flexible abrasives. It is a synthetic aluminium oxide (Al2O3, the same mineral from which rubies and sapphires are made) obtained by smelting bauxite at high temperature (3000 °C). It is a particularly hard mineral (9 on the mohs scale) but also resistant to impact and wear, characteristics that make it still today the most widely used mineral in the manufacture of abrasive belts, flap wheels, pin wheels, abrasive rings and many other of our products.
SILICON CARBIDE
Another synthetic mineral, a mix of carbon and silicon (SiC) created in the late 1800s in an attempt to find a better performing mineral than aluminium oxide. It is indeed an extremely hard mineral (9.5 on the mohs scale, so very close to diamond), but also very brittle. This fragility makes it only suitable for machining materials that are more fragile than it is (glass, ceramics, plastics, cast iron and bronze), while for the manufacture of abrasive belts for use on most metals, aluminium oxide is still the best choice.
ZIRCONIUM
It is an evolution of corundum. Again obtained by fusion at very high temperature, a certain percentage (around 25-30%) of zirconium oxide (ZrO2) is mixed with aluminium oxide (Al2O3). The result is a mineral that is slightly less hard than aluminium oxide, but definitely more tenacious. This higher toughness makes it better than aluminium oxide in the machining (abrasive belt or flap wheel) of difficult materials such as stainless steels. This difference in performance diminishes in finer grits.
CERAMIC ABRASIVE
The highest performing abrasive grain available. Here, too, we are dealing with an evolution of corundum, which is reduced to a very fine powder (in the order of a thousandth of a millimetre) and then recompacted and subjected to a sintering process (at around 1300 °C). The resulting solid is then crushed to obtain the desired size abrasive grain. The result is a mineral of comparable hardness to the aluminium oxide from which it started, but with a very uniform internal structure that allows it to wear down optimally during the abrasion process, making it the best choice for machining difficult materials (stainless and alloy steels), and for heavy stock removal. consiglio abrasivi produces a wide range of tools with ceramic abrasive: abrasive belts, flap wheels, flap wheels with pivots, reinforced rings, flap discs, velcro discs and much more.