Methods of titanium alloy machining by cutting and clamping

Titanium alloy, as a new structural material that has emerged in recent years, shines brightly in various fields such as aerospace, shipbuilding and health care due to its low density, high specific strength, low coefficient of thermal expansion and excellent high-temperature mechanical properties and corrosion resistance. However, titanium alloy's high coefficient of friction, tendency to oxidize, and propensity to ignite under high-temperature and high-speed friction present significant challenges to its machining. How to improve the cutting properties of titanium alloy parts and ensure that the workpieces meet the expected specifications is a key technical problem to be solved in titanium alloy applications.

I. Main problems encountered in titanium alloy machining by cutting and clamping

1. High cutting temperature: The heat generated when machining titanium alloy is difficult to dissipate effectively, resulting in consistently high cutting temperatures.
2. Strong tool sticking: The adhesion force between titanium alloy and cutting tool is high, which can easily cause tool sticking, affecting machining efficiency and workpiece quality.
3. High cutting torque: The high strength of the titanium alloy increases the torque required during the cutting process, placing higher demands on the machine and cutting tool.
4. Low modulus of elasticity and high yield strength to tensile strength ratio: Titanium alloy has significant elastic deformation during machining, making it prone to rebound, and its yield strength to tensile strength ratio is high, making it difficult to machine.
5. High pressure on the cutting edge: During titanium alloy machining, the cutting edge of the tool is subjected to high pressure, which can easily lead to tool wear and breakage.

II. Improvement strategies and implementation plans

In response to the aforementioned challenges, we propose the following improvement strategies:

1. Optimum selection of cutting tool materials:
   • Select cutting tool materials with high strength and good wear resistance, such as hard alloy or ceramic cutting tools, to improve the durability and cutting properties of the tool.
2. Improved drill geometry:
   • Use twist drills with increased cutting edge width, core diameter and sharpening angle to improve cutting conditions, reduce cutting force and cutting temperature.
3. Corresponding adjustment of the thread bore diameter:
   • When machining a threaded hole, the drill bit diameter can be appropriately increased to reduce cutting resistance and improve machining efficiency.
4. Use of special tap designs:
   • Select taps with special designs, such as spiral taps or coated taps, to improve chip evacuation and lubrication conditions during tapping.
5. Intelligent selection of the thread cutting speed:
   • Based on the characteristics and machining requirements of titanium alloy, it is reasonable to choose the threading speed to avoid overheating and tool sticking.
6. Scientific selection of cutting fluids:
   • Select cutting fluids with good cooling, lubrication and corrosion protection properties to effectively reduce cutting temperature, reduce tool wear and improve machining quality and efficiency.