Methods to Prevent Deformation Caused by Heat Treatment of Precision Injection Molds

In the heat treatment process, precision injection molding molds often deform. In order to prevent this bad phenomenon, as long as you grasp the law of deformation, analyze its causes, and use different methods to prevent it, the deformation phenomenon of the mold can be reduced. Generally speaking, the heat treatment deformation of plastic injection mold and molding can be prevented by the following methods.

1. Choose the right materials. For precision injection molding, micro-deformed mold steels with good materials should be selected, and mold steels with severe carbide segregation should be cast, and larger and uncastable mold steels should be subjected to solid solution double refinement heat treatment.

2. The mold structure design should be reasonable, the thickness should not be too large, the shape should be symmetrical. The deformation law should be grasped for the larger deformation mold, and the processing allowance should be reserved. For the large and precision injection mold, we can apply the combined structure.

3. The precision injection mold must be pre-heated to eliminate the residual stress generated during the machining process.

4. Reasonably select the heating temperature and control the heating speed. For precision injection molds, slow heating, preheating and other balanced heating methods can be adopted to reduce the heat treatment deformation of the mold.

5. Under the condition of ensuring the hardness of the injection mold, try to use pre-cooling, hierarchical cooling quenching or warm quenching process.

6. For precision injection molds, if the premise permits, try to use vacuum heating and quenching and cryogenic treatment after quenching.

7. For some sophisticated molds, pre-heat treatment, aging heat treatment, tempering and nitriding heat treatment can be used to control the accuracy of the mold.

8. When repairing mold blisters, pores, abrasion and other defects, use cold welders and other repair equipment with low thermal impact to avoid deformation during the repair process.

There are many methods for heat treatment, including hole plugging, tying, mechanical fixing, heating, cooling, etc. A suitable tempering heat treatment process is also an effective measure to reduce the deformation of precision injection molds.