Analysis Of CNC Machining Process For Titanium Alloy Parts

The core difficulties in CNC machining of titanium alloys are easy heat accumulation during cutting, rapid tool wear, and easy workpiece deformation. The process should focus on temperature control, wear resistance, and deformation prevention, combined with the part structure, precision, and alloy grade to formulate a layered machining plan and optimize parameters. The key preparation points are as follows:

 

 

1.Raw Materials and Pre-treatment

TC4 is commonly used for aerospace parts, and pure titanium TA2 for medical parts, with significant differences in machinability. Blanks need annealing to eliminate internal stress, remove oxide scale and impurities, reduce deformation, and protect cutting tools.

 

2.Tool and Equipment Selection

YG-type cemented carbide or TiAlN/AlTiN coated tools can extend service life by about 40%; tools adopt 5°–15° positive rake angle and variable helix groove design. High-rigidity multi-axis machining centers are selected for equipment, and 5-axis linkage machining is preferred for complex parts.

 

3.Programming and Fixturing

Spiral interpolation and layered milling are adopted, with reasonable cutting parameters set; fixtures ensure rigidity, and auxiliary supports are added for thin-walled parts to prevent springback and deformation.

 

 

CNC machining of titanium alloys is carried out in layers: rough machining for material removal, semi-finishing for profile correction, and finishing for precision assurance, with parameter optimization step by step.

 

1.Rough Machining: Focus on efficient material removal, adopt climb milling to reduce impact, and reasonably control feed rate and spindle speed to prevent heat accumulation. Cutting depth is 0.5–2 mm, matched with high-pressure cooling fluid for timely chip removal to avoid aggravated tool wear caused by accumulation of serrated chips.

 

2.Semi-finishing: Correct errors from rough machining and prepare for finishing. Cutting depth is reduced to 0.2–0.5 mm, with stable feed and optimized tool paths; small-diameter milling cutters can be used for complex curved surfaces to ensure smooth contours.

 

3.Finishing: Ensure dimensional and surface quality, with cutting depth controlled at 0.1–0.2 mm, reduced feed rate, and sharp tools used. Direct cooling of cutting edges to reduce temperature; ultra-high-precision parts require machining in a constant-temperature environment.

 

 

Post-treatment mainly includes deburring, surface treatment, and quality inspection. Deburring is done manually or mechanically to avoid affecting assembly and use; anodizing, sandblasting, etc., are adopted to improve corrosion resistance and appearance, and remove oxide layers; coordinate measuring machines and other equipment are used to inspect dimensions, roughness, and geometric tolerances, and unqualified parts are reworked or scrapped in a timely manner.

 

 

1.Thermal Management: Titanium alloy has poor thermal conductivity, and cutting heat tends to accumulate and damage tools. High-pressure oil-based or oil-mist cooling fluid must be used throughout the process, with flow rate controlled to ensure cooling and chip removal effects.

 

2.Vibration Control: Due to low elastic modulus, workpiece springback and tool vibration are prone to occur. Fixtures should be optimized, tool overhang shortened, anti-vibration tools and reasonable tool paths adopted to reduce the impact of vibration on precision.

 

3.Work Hardening Control: Titanium alloy is prone to work hardening. Stable chip load must be maintained, cutting depth reasonably controlled, and tool friction on the workpiece avoided to aggravate hardening.

 

4.Chip Handling: Serrated chips are easy to adhere. Peck drilling cycles, high-pressure air flow, etc., should be used for timely chip removal to prevent secondary cutting and tool wear.

 

Ruihang Group mainly produces Titanium and Titanium Alloy products with the complete industry chain,including smelting,forging, straightening,rolling,surface treating,testing process.We are a technology and innovation enterprise that integrates R&D, production and sales into one integrated system.For any purchasing needs, feel free to contact us at email: Sam.Rui@bjrh-titanium.com