The production technology of aluminum castings mainly covers three: pressure casting, gravity casting, and extrusion casting.
Pressure casting, also known as die casting, involves the rapid injection of molten aluminum or aluminum alloy into mold cavity under the action of external force. This method can be further subdivided into vacuum casting, centrifugal casting, low-pressure casting, and pressure casting.
In the gravity casting process, molten aluminum or aluminum alloy flows into the mold cavity designed in advance by the action of its own weight. Gravity casting can be further divided into casting and hard mold casting. Since sand casting has the characteristics of low mold cost and simple operation process, it is suitable for the production of single or large-scale aluminum parts Hard mold casting, also known as metal mold casting, uses metal molds for production, and its molds have high strength characteristics and support recycling.
Extrusion casting also known as liquid state forging technology, involves injecting molten aluminum or aluminum alloy into an open mold, then closing the mold and applying high pressure to cause the aluminum or alloy material in the mold to undergo plastic flow and deformation, and finally generating the required aluminum casting.
When manufacturing aluminum castings, it is particularly important to control the casting to avoid large shrinkage stress and hot cracks. Castings should conform to specified dimensions and deviations, and should not have defects such as cracks, cold shuts, sand holes, pores. The casting temperature should be appropriate to ensure good fluidity of the molten metal and to reduce the organization stress. The non-machined surface of the casting should be and flat, and the casting marks should be clear. When designing, the part structure should be reasonably laid out, the wall thickness design should be optimized, the cross-section thickness be kept uniform, and the generation of shrinkage holes and sand holes should be avoided.
There are many manufacturing methods for aluminum castings, each with its own characteristics application scenarios, and the selection should be made according to specific needs. During the production process, each detail should be paid special attention to ensure the quality of the casting.
