A356 Casting T6 Heat Treatment Deformation, Bulging, and Mold Pre Deformation Compensation Design | Wheel Hub and Structural Component Control Deformation
After heat treatment, casting warping, bulging, and dimensional deviations are caused by 45% of internal stresses during casting solidification, which can be pre compensated during the mold stage.
The thickness and cross-sectional difference of castings are large, and the solidification shrinkage stress is uneven. After T6 solid solution treatment, stress is released, resulting in irreversible deformation.
The mold did not undergo reverse pre deformation, resulting in elliptical wheel rims and warped installation surfaces after heat treatment, and insufficient machining allowance on one side.
The demolding temperature of the casting is too high, and after demolding, it cools and deforms freely. The initial internal stress is doubled, and the heat treatment deformation is intensified.
The support point of the heat treatment fixture is unreasonable, and the casting self weight creep under high temperature solid solution, combined with the original stress deformation.
Uneven cooling in different positions of the same mold cavity, inconsistent stress distribution in the casting body, and fluctuating deformation per mold.
Low pressure die-casting molds (LPDC), reverse pressure casting molds (CPC), differential pressure casting molds for wheel hubs, low-pressure casting molds for wheel hubs, gravity casting molds, motorcycle wheel hub casting molds, structural component casting molds, aluminum alloy wheel hub molds, aluminum casting forming molds, low-pressure casting tooling molds, automotive parts, and new energy structural components have strict requirements for dimensional tolerances after heat treatment. Zhejiang Xinfeng Machinery Plan: First, sample the mold, measure the actual deformation vector after T6, and perform reverse pre deformation compensation in the mold cavity; Priority radial pre compensation for elliptical wheel rims. Control the demolding temperature within the range of 280-320 ℃, slowly release some stress through air cooling, and reduce the deformation amplitude of heat treatment. The symmetrical and balanced design of the cooling water circuit reduces the inherent internal stress of the casting. Many overseas customers indicate T6 dimensions on their drawings, and it is necessary to confirm with the customer in advance whether it is the as cast size or the size after heat treatment to avoid acceptance disputes.
FAQ
1. Question: What is the optimal temperature range for controlling deformation during demolding?
Answer: Demoulding at 280-320 ℃ reduces residual stress.
2. Question: What data is used to determine the pre deformation of the mold?
Answer: The measured deformation vector after the T6 test module.
3. Question: What are the core risks of castings with significant differences in cross-sectional thickness?
Answer: Uneven solidification stress and warping after heat treatment release.
4. Question: What is the impact of heat treatment fixtures?
Answer: Improper support can cause high-temperature self weight creep and additional deformation.
5. Question: What are the consequences of uneven cooling in the mold cavity?
Answer: The deformation of each mold is unstable and the size fluctuates greatly.
6. Question: What are the key points for confirming dimensions before accepting an order?
Answer: Clarify whether the acceptance criteria are as cast or after T6 heat treatment.
