Isothermal is a new technology developed based on traditional die forging technology. Different from ordinary die forging technology, it heats the die and billet to the forging temperature at the same time. This allows the billet to complete the deformation process in a narrow range of temperature changes.
The advantages of isothermal forging are:
- Greatly reduces the rheological resistance of the metal, and its total pressure is equivalent to 10-20% of ordinary die forging. Save equipment investment and power consumption.
- Significantly improve the plasticity of metal materials. Therefore, the billet has good fluidity, and it is easy to fill the mold cavity. After forging, the dimensional accuracy of the workpiece is high, and the machining allowance is small, even without machining.
- Isothermal forging technology can make forgings with complex shapes, thin walls, and high ribs formed at a go. The ordinary die forging technology requires multiple formings for special difficult-to-deform alloys.
- In the isothermal forging process, due to the uniform deformation temperature, the metal can maintain a relatively uniform and fine equiaxed grain structure. So the product has low yield strength, low-frequency fatigue, and high-stress corrosion resistance.
- The material utilization rate is high. The metal consumption of isothermal die forging is lower by more than 50% compared to ordinary die forging.
3 Categories of isothermal forging
- Isothermal precision die forging
Metals forged under isothermal conditions obtains forgings with small or no inclination and small or no allowance. This method can produce some structural forgings with complex shapes and general dimensional accuracy requirements. It is also good for high-stress conditions and shapes close to the shape of the parts.
- Isothermal superplastic die forging
Metals exhibit high plasticity not only under isothermal conditions but also under extremely low deformation rates (10-4/s). This is for the hard-to-deform metals can obtain the required metallurgical structure, shape, and size.
- Powder alloy isothermal forging
This kind of process method uses powder metallurgy to perform as the original blank for isothermal forging. Under the condition of isothermal superplasticity, the blank is greatly deformed. The blank is compacted, thereby obtaining a forging that meets the process requirements.
Suitable steel grades for isothermal forging are titanium alloy, superalloy, aluminum alloy, and magnesium alloy. The forgings are common in aerospace and aviation industries, as well as precision forming of hard-to-deform alloy forgings of new materials.
Isothermal forging technology not only improves the utilization rate of metal materials but also reduces the consumption of subsequent machining allowances and machining hours. It has high technical and economic benefits.