1, Essence of Materials and Manufacturing Process
Aluminum billet: usually refers to aluminum blocks or profiles that have not been further processed or have only been preliminarily cut or trimmed. It retains the original physical and chemical properties of aluminum and is the basic material for subsequent processing such as forging, extrusion, cutting, etc. The manufacturing process of aluminum billets is relatively simple, mainly involving the melting, casting (or direct extrusion molding), and preliminary cooling and cutting of aluminum ingots.
Cast aluminum: It is the process of injecting molten aluminum into a mold through casting technology, and then cooling and solidifying it to form aluminum products of the desired shape and size. The aluminum casting process can produce parts with complex shapes and uneven wall thickness, and the cost is relatively low, making it suitable for large-scale production. However, defects such as shrinkage and porosity that may occur during the casting process, as well as uneven microstructure caused by uneven cooling rates, can all affect the mechanical properties of cast aluminum.
2, Microstructure and mechanical properties
Microstructure: Due to the lack of complex processing, the microstructure of aluminum billets is relatively uniform, with moderate grain size and fewer defects. However, cast aluminum may have significant differences in microstructure due to the characteristics of the casting process, such as coarse grains, uneven microstructure, and the presence of pores and shrinkage cavities. These microstructural differences directly affect the mechanical properties of the material.
Mechanical properties: In terms of strength, including tensile strength, yield strength, hardness, and fatigue resistance, aluminum billets often exhibit superior performance. This is mainly due to its relatively uniform microstructure and fewer internal defects. In contrast, cast aluminum may have certain fluctuations in mechanical properties, especially in critical stress areas, where its mechanical properties may be severely affected by internal defects.
