Castings, also known as forgings, are metal parts or blanks with specific shapes, dimensions, and properties obtained by pouring molten metal into a mold of a specific shape through a casting process, allowing it to cool and solidify.
This process combines knowledge from multiple disciplines such as metallurgy, materials science, and mechanical engineering, and is an indispensable part of modern manufacturing.
The manufacturing processes for castings are diverse, mainly including sand casting, special casting (such as lost foam casting and pressure casting), and continuous casting. Sand casting is the most traditional and widely used casting method. It uses molding sand as the molding material and completes the production of castings through steps such as pattern making, mold preparation, mold assembly, pouring, shakeout, and cleaning. Special casting, on the other hand, is designed for specific needs, such as high precision, complex shapes, or special materials, and employs more advanced processes and equipment. For example, lost foam casting uses foam plastic patterns that disappear during pouring, thus obtaining high-precision castings.
Castings offer significant performance advantages. First, they can be used to manufacture parts with complex shapes that are difficult to achieve through other machining methods, such as engine blocks and cylinder heads with intricate internal structures. Second, castings offer a wide range of material choices, from common cast iron and cast steel to aluminum alloys and copper alloys, all of which can be selected to meet different mechanical property and corrosion resistance requirements. Furthermore, castings are cost-effective, especially in mass production, where their unit cost is relatively low, making them suitable for large-scale industrial production.