Countermeasures for difficult processing of titanium alloys

1. Cooling
Using coolant to reduce cutting temperature. Generally, non-soluble oil coolant is suitable for low-speed heavy-load cutting, while soluble cutting coolant is suitable for high-speed cutting.
In addition, the low-temperature cutting method can be employed. For instance, using liquid nitrogen (-180℃) or liquid CO2 (-76℃) as the cutting fluid can effectively lower the temperature in the cutting area, improve the surface quality of the processed product, and extend the lifespan of the cutting tools.

2. Select the appropriate cutting tools
Choosing the appropriate cutting tools can significantly enhance processing efficiency. Since the heat of titanium alloys is mainly dissipated through the cutting edge and coolant, rather than being expelled through chips like in steel, the tiny part of the cutting edge has to bear extremely high heat and mechanical stress. Keeping the cutting edge sharp can reduce cutting force.
Furthermore, the use of grinding technology with polished grooves and high rake angle replaceable inserts also helps to reduce cutting pressure.
When necessary, coated cutting tools can also be used to reduce the viscosity of the alloy and break long chips. This not only reduces the friction during the chip removal process, but also helps to control the heat generated during the machining.

3. Maintain constant feed or increase the feed rate
Titanium alloys are prone to hardening during the processing stage. That is, during the cutting process, the hardness of titanium alloys will increase, which will accelerate the wear of the tools. Therefore, maintaining a constant feed rate is crucial for minimizing the degree of processing hardening.
Of course, if the equipment performance permits, it is possible to try increasing the feed rate. Doing so can reduce the time that the cutting tool spends in the processing area, thereby minimizing the accumulation of heat and the chances of material hardening during the machining process.

4. Reduce the cutting speed
Control the heat release and use a cutting speed of 1/3 or less of the steel's speed for titanium alloy processing.

5. Replace the cutting tools according to the process.
When processing titanium alloys, the lifespan of ceramic, titanium carbide and titanium nitride coated cutting tools is relatively short. Generally, for large-scale titanium alloy processing, hard steel tools are the preferred choice; while for small-scale processing, high-speed cemented carbide tools are more suitable.
At present, the ultrasonic processing technology is under development. Its aim is to extend the service life of the cutting tools by reducing the contact time between the tools and the workpiece.

6. Utilize high-stiffness machine tools
High rigidity machine tools are crucial for the successful processing of titanium alloys. An ideal titanium alloy milling machine must be rigid, with the spindle capable of operating at low speeds and high torques to absorb vibrations and reduce chatter during the cutting process.

7. Regular cleaning
Regularly clean the processing equipment and tools to prevent debris from accumulating, which could affect the processing results.