Why does deep bed filter is important for aluminum alloy

High quality of ingots is required for 3104 aluminum alloy for can-body materials． In the casting process， inclusions in the ingots damage the quality of the final products． On the production line of a certain aluminum processing plant， Prefil-Footprint was used to extract samples at the outlet of its deep bed filter． The main varieties of inclusions in 3104 aluminum alloy were figured out by the metallographic analysis and SEM analysis， and the amount variation of inclusions was analyzed through the quantitative method． The inclusions in 3104 aluminum alloy mainly included oxide inclusions and a small amount of TiB2 inclusions could also exist． The deep bed filter could remove all kinds of inclusions． While the effect of filtering was weak in the initial stage of use， as the increase of amount of the melt which had been filtered， the effect became better and more stable．

3104 aluminum alloy has the advantages of high strength, good toughness, strong corrosion resistance, and good deep drawing performance. It is the main material for cans after 3004 aluminum alloy. It is generally believed that the higher the magnesium content in the can alloy, the higher the strip strength…. The presence of magnesium makes it easy to produce oxidative burn loss during the casting process, which is one of the main sources of inclusions. 3104 aluminum alloy needs to be processed by hot rolling, cold rolling, and deep drawing in the production process of pop-top cans, which requires high melt quality and ingot quality. More advanced filters are usually used for melt purification in production, deep bed filtration is one of the most commonly used filters. The deep bed filter is composed of several layers of alumina balls and appropriately sized alumina grit layers stacked in a unique way, with a filter media thickness of 500 mm. The size and stacking of alumina balls and gravel should be adjusted for different alloys. Inclusions are mainly adsorbed on the surface of the medium in four ways: direct interception, Brownian motion, inertial force, and gravitational precipitation. At present, the world's largest aluminum companies have their own deep bed filter technology, such as:

Alcoa (Alcoa), Alcan (Alcan), Novelis (Alcoa), etc. This depth filtration technology has been recognized in the foundry field and can meet the needs of high-end products with high-quality requirements. The deep bed filter has the advantages of low production cost, large filtering area, and high filtering efficiency. For impurities larger than 5 bucket m, the filtering efficiency is greater than 90%. How to use deep bed filters efficiently directly affects product quality, production efficiency, and cost.

The Prefil-footprint slag measuring instrument uses the filter press method to filter and enrich the inclusions in the melt, which is a relatively advanced slag measuring method in the world. 4 J. This article uses Prefil. The footprint slag measuring instrument takes samples at the production site of an aluminum processing plant, analyzes the type and quantity of inclusions in the sample, and guides the on-site use of the deep bed filter through the analysis results.