1. Aluminum: Aluminum is a lively metal. A dense oxide film with a thickness of about 50 angstroms (1 angstrom = 0.1 nanometers) is immediately formed on the surface of aluminum in dry air, so that aluminum will not be further oxidized and resistant to water; but aluminum powder and air Mixing is very easy to burn; molten aluminum can violently correspond to the metal of water; aluminum is amphoteric, very soluble in strong alkalis, and also soluble in dilute acids.
2. Cast aluminum: attention should be paid to prevent the melt from overheating, especially when the furnace temperature is as high as 1200℃ during smelting in a natural gas furnace (or gas furnace), local overheating is likely to occur at such a high temperature. For this reason, when the charge is melted, the melt should be properly agitated to make the temperature in the molten pool uniform, and it is also helpful to accelerate the melting.