I. Characteristics of the precision forging process and its technical advantages
The use of precision forging machines to produce titanium and titanium alloy forgings has the following significant characteristics:
1. High-frequency forging: The frequency of the hammer head reaches hundreds to thousands of times per minute, which reduces the friction coefficient and ensures that the surface of the forging is smooth and the internal structure is uniform.
2. Small deformation design: The deformation of a single stroke is small, the contact area is small, the deformation force is reduced, the equipment tonnage demand is reduced, and the tool life is extended.
3. Dynamic process adjustment: The hammerhead stroke is adjustable, which is suitable for the production of forged bars of different sizes, and there is no need to frequently change the mold.
4. High dimensional accuracy: Four hammerheads are synchronously forged with constant stroke to ensure titanium alloy forgings dimensional consistency.
5. Isothermal forging control: The temperature drop is compensated by adjusting the feed amount to maintain a stable deformation temperature.
6. Axial extension guide: The arc groove hammerhead design suppresses circumferential stress and avoids the generation of edges and cracks.
7. Three-way compressive stress strengthening: improve metal plasticity (forging ratio of pure titanium 6:1, alloy 4:1), promote densification.
8. Thermal effect management: A large reduction may lead to excessive temperature rise (such as TC11 alloy up to 90℃), and grain coarsening needs to be prevented.
II. Causes and prevention measures of flaw detection defects
1. Common defect types
Internal cracks: mostly caused by uneven deformation or improper temperature control, resulting in local stress concentration.
Porosity/inclusions: insufficient purity of raw materials or residual oxidation inclusions during the titanium alloy forgings process.
2. Process optimization direction
Parameter refinement: control the pass reduction and forging frequency, balance thermal effect, and microstructure refinement.
Material pretreatment: strengthen billet flaw detection and surface treatment to reduce original defects.
Equipment maintenance: regularly calibrate the hammer centering to avoid defects caused by eccentric loading.
III. Conclusion
Precision forging technology has become the preferred solution for titanium alloy forgings production due to its high efficiency and precision, but the process needs to be continuously optimized in combination with defect analysis. By dynamically monitoring forging temperature, stress field distribution, and material flow behavior, the defect rate can be further reduced and the comprehensive performance of titanium alloy forgings can be improved.
