The temperature during the smelting process is controlled at 720~760°C. After the aluminum ingot is partially melted, raw materials with higher melting points such as Si element and Ti agent are added. Ti forms heterogeneous crystal nuclei in the alloy, which plays a role in refining the structure. It is pressed into Melt in molten aluminum to reduce burning loss. After the aluminum ingot is basically completely melted, add alloying elements such as Mg and Cu that are easy to burn. It should not be added too early to reduce burning loss, nor too late to affect diffusion and cause segregation. Close the furnace door and continue melting.
After smelting is completed, there is a lot of scum on the surface of the aluminum alloy, mainly Al2O3 and other oxide slag inclusions. These fine slag inclusions are heavier than the molten aluminum, but have a lighter specific gravity after agglomeration and agglomeration, so they float on the surface and need to be cleaned. The amount of slag cleaning agent is added at 0.2% to 0.5%, sprinkle evenly on the surface of the aluminum liquid, and stir lightly and evenly. Put the slag on the furnace door, close the furnace door and let it sit.
On the one hand, the slag cleaning agent has a heating effect and can melt the aluminum liquid adhering to the scum; on the other hand, it can effectively separate the slag from the aluminum liquid, which is conducive to the removal. Aluminum slag, let it sit for a few minutes and then steadily remove the aluminum slag from the furnace door. Aluminum alloy smelting is a very complex process. The degree of burning loss of different elements is inconsistent. Before transferring the aluminum liquid into the transfer ladle after slag removal, samples need to be taken for physical and chemical analysis to ensure that each element is within the qualified range before water can be released into the transfer ladle. The ladle is degassed and refined, otherwise appropriate adjustments are required if it fails.
