BROWN  ALUMINIUM  OXIDE
SYMBOL :  A

Brown aluminium oxide is fused in an electrical furnace byhig
temperature. Its main raw materials are bauxite, anthracite. Itdispaly
brown.Its chemical composition contains Al2O3, a small amount ofSiO2??????
TiO2??????and Fe2O3, etc. The microhardness is 1800 -2200 kg/mm2,The
toughness is higher than silicon carbide. Abrasive articles made ofit are
suited forgrinding metals of highten sile strength such assteel,annealed
malleableiron and hard high - class refractory products. The degreeof
refractory is up to 1850 C.