Types of Metal Casting Processes

In many ways, the metal casting process has changed little since its inception thousands of years ago. Even with today's technological advancements and advanced production methods, the way metal casting remains the same, molds and molten metal are still used. Many centuries of evolution have seen the development of a more precise and automated method of producing high-quality products.

Metal casting has come a long way, increasing efficiency and output. Unlike the Egyptians, Greeks and Romans, modern engineers can easily design parts and put them into production because much of the development of molds and castings is done through automation and electronics. Countless products are produced every day that fill store shelves and are used as parts for cars, airplanes, and spacecraft.

Every device we use is produced through a metal casting process. The biggest difference between metal casting today and the process of a hundred years ago is the amount of planning, precision, design and tolerances achieved through computerization and automation. Cores and molds are more detailed and precise down to the smallest details and parts.

Metal casting begins with a design pattern, which is a model of the item to be cast. Molding is the complex process of shaping a mold cavity with precise dimensions. Once the item has solidified and cooled in the mold, it must be prepared so that it can be removed from the mold without breaking, which means taking into account shrinkage during solidification and possible deformation. The model must include a way to feed the liquid metal into the mold. Any mistakes in model development can lead to defects and casting failures.

Core making is suitable for parts with internal cavities and is not suitable for all metal casting processes. It is most commonly used in sand casting, die casting and injection molding. When the casting is hollow, sand or metal (called a core) shapes the interior of the model. The core is strong but foldable and easily removed at the end of the casting process. The use of cores allows the creation of complex designs, such as holes or special chambers. When casting an automatic engine, five cores are needed to produce the chambers needed for an internal combustion engine.

Forming is the process of making model castings. During the casting process, the molds are held in a frame called a flask. One type of sand is forced into the flask around the pattern that creates the mold. Once formed, the pattern is removed, leaving the casting. Once the mold design is complete, it can be fired according to the material to harden it and prepare it for molten metal.

The next step is to melt the metal so that it can be poured into the mold through channels or holes called gates. Once the molten metal hardens, the mold is shaken or vibrated to remove sand from the casting, which is then collected for reuse.The final step in the process is cleaning the product. Remove excess molding material and misshapen and jagged edges. The product is processed into its final form and shaped. It can be polished according to its specifications.