The high precision of gravity casting molds is achieved through multi-faceted control and optimization, which is an important technology in the casting industry. In the gravity casting process, the precision of the mold directly affects the quality of the casting. Therefore, mold design, material selection, manufacturing process and quality control are all key factors affecting mold precision.
Mold design is an important link in the high precision of gravity casting molds. In the mold design process, it is necessary to consider the size, shape and structural characteristics of the casting, and reasonably design the mold cavity structure and placement position. By using design software such as CAD/CAM, the mold can be three-dimensionally modeled and mold flow analyzed to optimize the mold structure, reduce thermal stress and deformation, and improve the precision of the casting. At the same time, according to the specific application requirements, choosing the right mold material is also an important part of mold design.
The choice of mold material also has an important influence on the precision of gravity casting molds. The mold material needs to have good thermal conductivity and thermal stability to ensure that the casting can shrink evenly during the cooling process and reduce deformation. Common mold materials include cast iron, cast steel, aluminum alloy, etc., and the appropriate material is selected according to the specific application requirements. At the same time, strict quality inspection of the mold material is also required to ensure that its quality meets the standard requirements.
The processing accuracy and process control during mold manufacturing are crucial to the accuracy of gravity casting molds. The processing accuracy of molds includes the dimensional accuracy, surface roughness and shape accuracy of molds. In the mold manufacturing process, high-precision processing equipment and processes, such as CNC machining centers, wire cutting machines, etc., are required to ensure the accuracy requirements of the mold. At the same time, the heat treatment and surface treatment of the mold also need to be strictly controlled to improve the hardness and wear resistance of the mold.
The optimization and control of casting process parameters are also the key to achieving high precision of gravity casting molds. Casting process parameters include pouring temperature, pouring speed, cooling time, etc. By reasonably selecting and adjusting these parameters, the flow and solidification process of molten metal can be controlled, defects such as thermal stress and shrinkage holes can be reduced, and the accuracy of castings can be improved. At the same time, for large molds, segmented pouring can be used to reduce temperature gradients and thermal stresses and improve the overall accuracy of castings.