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Introduction
Deformation is a common defect in die casting, which not only reduces the precision, but also affects the appearance and mechanical properties of the casting. In response to this defect, continuous improvement and optimal control measures are needed. This article will discuss the causes of deformation in die casting and present effective measures to prevent and control it.
Causes of Deformation
Deformation of casting parts occurs mainly due to uneven cooling or shrinkage in the mold, which causes forces that are greater than thestrength or flowability of the material. Generally speaking, the common causes of deformation in die casting can be summarized as follows:
1. Poor material selection: Not all materials are suitable for die casting. If materials with high shrinkage rate, large flow ability and worse cosmetic surface quality are selected, or the mold material or thermal expansion temperature does not match with the material, it may cause deformation.
2. Improper process parameters: Improper process parameters, such as insufficient hydraulic pressure and injection speed, may result in poor filling and uneven cooling in the mold, causing casting deformation.
3. Uneven gate thickness: Uneven gate thickness will cause uneven cooling, resulting in part deformation.
4. Poor casting design: Poor casting design may result in casting getting stuck in the mold or too much weight stressing the castings, which may cause deformation.
5. Poor maintenance and repair of the mold: Improper maintenance and repair of the mold will reduce mold tightness and cause die casting deformation.
Prevention and Control Measures
To avoid deformation due to casting defects, the following preventive and control measures should be taken:
1. Select the right material: The material should be selected according to the part structure, size and strength requirements. The aggregate state and content of the material must be consistent with the shrinkage rate, flow ability, and surface quality of the die casting.
2. Optimize process parameters: The parameters for each process must be optimized. Under appropriate conditions, the injection speed and holding time should be selected to ensure smooth filling of the mold and uniform cooling.
3. Adjust the gate thickness and shape: The gate thickness should be adjusted according to the product structure and material properties. It is necessary to avoid sharp corners and design a round gate shape whenever possible to reduce stress concentration and improve heat dissipation.
4. Improve casting design: The design of the die casting parts should be improved to reduce the cooling time and reduce or avoid concentrated stress.
5. Properly maintain and repair the mold: It is important to maintain the tightness of the mold to a certain degree. If there are repair needs, it should be repaired in a timely manner.
Conclusion
To prevent die casting deformation, it is necessary to select the right material, optimize the process parameters, adjust the gate thickness and shape, improve the casting design, and properly maintain and repair the mold. Effective prevention and control measures can greatly reduce deformation and improve the quality of casting parts.
