Titanium alloys are increasingly used in the aviation manufacturing industry due to their high strength, good mechanical properties and strong corrosion resistance. As the proportion of titanium alloys in aircraft continues to increase, the CNC of titanium alloy aviation structural parts Processing efficiency has an increasing impact on aviation manufacturing companies. Titanium alloy is a difficult-to-machine material, with a relative machinability of 0.15 to 0.25 and a processing efficiency of only 10% of that of aluminum alloy. Therefore, the low processing efficiency of titanium alloy aerospace structural parts seriously restricts the mass production of modern aircraft. Achieving efficient processing of titanium alloy aerospace structural parts has become a topic of common concern to aerospace manufacturing companies, CNC equipment manufacturers and tool manufacturers.

01 Titanium alloy cutting performance

Titanium alloy has the characteristics of good mechanical properties, strong corrosion resistance and low specific gravity. However, during processing, the cutting performance of titanium alloy is very poor, which is mainly reflected in the following aspects:

(1) Large cutting force. Titanium alloy materials have high strength and generate large cutting resistance during cutting, resulting in a large amount of cutting heat generated at the cutting edge;

(2) Low thermal conductivity. Titanium alloy has low thermal diffusivity, and a large amount of cutting heat is concentrated in the cutting area;

(3) The tool tip stress is large. The plasticity of titanium alloy is low, and the chips generated during processing are very easy to bend, resulting in a short contact length between the chips and the rake face. Therefore, the force stored per unit area on the cutting edge increases, causing stress concentration at the tip;

(4) Large friction. The elastic modulus of titanium alloy is small, causing increased friction on the front and flank surfaces;

(5) High chemical activity. At high cutting temperatures, titanium can easily react chemically with hydrogen, oxygen, nitrogen and other gases in the air to form a surface hard layer, which accelerates tool wear.

02 Titanium alloy high-efficiency processing equipment

In order to meet the efficient processing of titanium alloy structural parts, new titanium alloy processing equipment shows the following development trends:

(1) Large torque. Titanium alloys have high strength and very large cutting forces during processing. An obvious feature of titanium alloy processing machine tools is the large spindle torque and swing angle torque.

(2) Application of electric spindle. High-power, high-torque electric spindles have been used in titanium alloy processing.

(3) Horizontal machining centers are used for titanium alloy processing. The horizontal machining center has convenient chip removal, which is beneficial to improving processing efficiency and processing quality. The exchangeable worktable makes it easy to realize multi-station processing and set up a flexible production line, improving equipment utilization.

(4) High-pressure internal cooling. In titanium alloy processing, cutting heat is concentrated on the tool tip, which can easily cause tool wear or damage. High-pressure internal coolant can be accurately sprayed into the cutting area to take away the cutting heat.

(5) Simulation optimization technology: The cutting allowance of titanium alloy structural parts will continue to change during rough machining. NC programs compiled by current CAM software can often only set fixed cutting parameters. In order to avoid the impact of local programs on tools and machine tools due to excessive cutting volume, the usual method is to ensure tool life and part quality by reducing the overall cutting parameters. , resulting in extremely low processing efficiency. Vericut's simulation optimization technology can solve this problem well. Set up the cutting parameter optimization library through Vericut software, and use the software to simulate. Through simulation, you can guess the actual machining allowance and cutting conditions, and optimize the cutting parameters in the program based on the machining allowance and cutting conditions. It not only extends the tool life, ensures the quality of parts, but also improves the processing efficiency.