Alumina CFF is used for aluminum alloy melt filtration and purification, it can be used to remove oxidized inclusions in molten aluminum.
Inclusions and gases in metals have significant effects on the strength, fatigue resistance, corrosion resistance and stress corrosion cracking of materials.
It has become the common goal of metallurgical, casting and material industries to effectively control the oxide inclusion in melt and improve the quality of casting rod and rolled plate.
At present, alumina CFF is widely used to remove inclusions from aluminum alloy melt.
Inclusion formation in aluminum alloy
Some inclusions in aluminum alloys come directly from the charge, while most of them are formed during smelting and pouring, mainly oxide inclusions.
All inclusions before casting are called primary oxidation inclusions.
Dispersed inclusions that cannot be completely removed after refining. It increases the viscosity of the metal melt and reduces the ability of aluminum to shrink during solidification.
Secondary oxidation inclusions are mainly formed during casting. When molten aluminum is cast, oxygen reacts with air to form oxidized inclusions.
Aluminum alloy in the smelting process and various components in the furnace gas contact, the formation of AL2O3 and other compounds.
Al2O3 in liquid aluminum increases the hydrogen content of residual aluminum melt.
Alumina ceramic foam filter technology came out in the 1970s, in the United States, Canada, Japan, France, Australia, Switzerland and other countries have been widely used.
Removal of inclusions in the aluminum melt is the most efficient method prior to the use of the foam ceramic filter plate filter port.
In recent years, some new purification technologies of liquid aluminum, such as vacuum dynamic treatment, ultrasonic continuous degassing and alumina CFF, have been studied at home and abroad and achieved good results.
As for the metal filter and fiber cloth filter, it can only remove the larger inclusions in the aluminum alloy melt, but the inclusion below micron level cannot be removed, and the metal filter will also cause pollution to the aluminum alloy.
The fine inclusions can be removed by using alumina CFF, and the mechanical properties and appearance quality of castings can be significantly improved.
