Liquid metal is poured into a mold cavity that matches the shape and size of the part. After cooling and solidification, it is used to obtain blanks or parts. This production method is commonly referred to as metal liquid forming or casting. The characteristics of liquid metal forming process, unlike lost foam casting, include: 1. Ability to produce parts with arbitrarily complex shapes, especially those with intricate internal cavities. 2. High adaptability, with no restrictions on the types of alloys and almost no limitations on the size of castings. 3. Wide range of material sources, recyclability of defective products, and low equipment investment. 4. High defect rate, relatively low surface quality, and poor working conditions.
Lost Foam Casting Foam Mold
In lost foam casting of steel castings, it is essential to appropriately control the density and volume of the white mold to ensure steady and orderly gas generation. The gas produced by the white mold, the gas discharged from the sand mold, and the gas precipitated in the alloy solution must all be promptly extracted by the vacuum pump or allowed to escape through the risers and slag collection risers of the pouring system.
Lost foam steel castings must also coordinate the suction directions of the vacuum pump from the top, middle, small, and bottom of the sandbox, as well as the law of hot air rising. This ensures thorough gas extraction and discharge. If suction is applied at the bottom of the sandbox while the vacuum pump's suction capacity is relatively low, but the amount of gas generated is significant, the casting may experience a situation where hot air rises in a certain cross-section while suction pulls downward. The conflict between these two forces can lead to the formation of a large number of pores.