Alpha alumina is one of the most important ceramic materials with properties and
applications having been thoroughly explored. Fused Cast Alpha Alumina block
comprises about 99% alumina (90% alpha alumina and 4% beta Al2O3), 0.4% SiO2 and
Alumina(Al2O3) is an aluminium compound with many crystalline forms or
polymorphs. Alumina exists in many forms, ?, ?, ?, ?, ?, ?, ?, ?. Alpha alumina
or corundum is the only thermodynamically stable form amongst the different
polymorphs. Alpha alumina stable at very high temperature and this property is
also used as refractory and thermal barrier.
Alumina is characterized with high compression strength, high hardness, good
resistance to abrasion, high resistance to chemical attack, high thermal
conductivity, good resistance to thermal shock, and high degree of
Its applications are widespread, and include spark plugs, tap washers, pump
seals, electronic substrates, grinding media, abrasion resistant tiles, cutting
tools, bioceramics, (hip-joints), body armour, laboratory ware and wear parts
for the textile and paper industries. It is also used in the manufacture of
monolithic and brick refractories. It is also used mixed with other materials
such as flake graphite for even more severe applications.
Fused Cast Alpha Alumina block is relatively resistant to molten glass corrosive
action, though not at the level of Baddeleyite. Most importantly, it does not
develop a passivation layer like fused cast AZS refractory. It dissolves slowly
in the glass through a concentration gradient at the contact surface.
Temperature and glass velocity tangential to the surface determine the corrosion
Fused cast alpha alumina block is an ideal product for the lower temperature
zones of the glass melting furnaces due to its high density, superior corrosion
resistance and low blister potential. It is also an ideal material for
Metallurgical Titanium Furnace because the superior thermal stability.
Sunrise refractory offers high quality fused cast alpha alumina blocks at a
competitive price for glass furnaces.
- posted 5 years ago