Titanium Alloy High-Precision Mass Turning Process Techniques

Titanium alloy is a typical difficult material to machine. It features low thermal conductivity, high chemical reactivity, low elastic modulus, and strong work hardening tendency. These properties pose numerous challenges to high-precision and mass turning, such as rapid tool wear, difficulty in controlling machining accuracy, and low production efficiency. It may severely restrict the large-scale production of titanium alloy components.

 

 

(1) Tool Material

Titanium alloy turning makes high cutting temperatures and it leads to easy chip adhesion and tool damage. Tools must be resistant to high temperatures, adhesion, and possess high toughness and wear resistance. Cemented carbide tools with ultra-fine grain substrates and TiAlN/AlCrN composite coatings are preferred for both roughing and finishing. YG-series alloys are used for roughing and PCBN or diamond-coated tools are optional for finishing. YT-series alloys are not used.

 

(2) Tool Geometric Parameters

Rake angle: 8°–12°, relief angle: 8°–15°, to reduce cutting load and temperature rise;

Nose radius: 0.4–1.2 mm, inclination angle: -5°–0°, adapting to different machining conditions and improving stability;

Wide and shallow chip breakers combined with chip splitters are adopted to ensure smooth chip evacuation and avoid workpiece damage.

 

(3) Tool Structure

Equipped with high-rigidity tool holders, high-pressure internal cooling structures, and modular tool shanks to reduce vibration, achieve efficient cooling, suppress built-up edge, and balance machining accuracy and mass production efficiency.

 

 

(1) Roughing Parameters

Roughing focuses on rapid stock removal and work hardening suppression, following the principles of low speed, large feed, and reasonable depth of cut. Control the cutting speed, feed rate and depth of cut. Most of the stock is removed in a single pass to balance tool life and machining stability.

 

(2) Finishing Parameters

Finishing prioritizes accuracy and surface quality, adopting medium-high speed, small feed, and small depth of cut. Control the cutting speed, feed rate and depth of cut to ensure stable cutting without vibration or hardening.

 

(3) Parameter Adjustment

Reduce cutting parameters for high-strength titanium alloys; increase speed for low-strength grades to improve efficiency. For thin-walled, slender shafts prone to deformation, reduce depth of cut and feed rate, and adopt sectional machining if necessary.

 

 

(1) Clamping Methods

Use double centers or chuck + center clamping to improve coaxiality and rigidity. Control clamping force and protect workpieces with soft jaws and copper pads.

Elastic and hydraulic fixtures are selected for thin-walled parts to distribute clamping force; special eccentric fixtures are used for eccentric parts to avoid inefficient and low-rigidity clamping.

Adopt modular fixtures for rapid clamping and changeover; regularly inspect fixture accuracy to ensure stability in mass production.

 

(2) Positioning Reference

Unify machining positioning references, adopt one surface with two pins positioning, and share the same reference for multiple processes to reduce accumulated errors. Precisely finish the reference surface in advance; rough turn forgings to remove scale first, ensuring reliable positioning and reducing machining deviations.

 

 

(1) Cutting Fluid Selection

Special sulfur, phosphorus, and chlorine-free fully synthetic cutting fluid is selected for titanium alloy turning, featuring excellent cooling, lubrication, rust prevention, and anti-adhesion properties to reduce chip buildup and extend tool life.

 

(2) Cooling Method

Conventional external cooling has limited effect. High-pressure internal cooling is preferred for mass production, delivering coolant directly to the cutting zone for efficient cooling and BUE suppression, combined with full-domain cooling to ensure stable machining.

 

(3) Cutting Fluid Management

Regularly test cutting fluid concentration, pH value, and cleanliness; filter impurities, replenish or replace fluid in a timely manner, and control fluid temperature to maintain stable lubrication and cooling effects.

 

 

(1) Blank Control

Inspect the appearance, dimensions, and internal quality of titanium alloy blanks before machining to eliminate defective parts; conduct stress relief annealing in advance to reduce machining deformation.

 

(2) Tool Management

Standardize tool service life and replacement cycles; regularly regrind, inspect, and test-cut tools for verification. Monitor wear in real time to prevent batch dimensional deviations.

 

(3) Equipment Maintenance

Calibrate machine tool accuracy before production; regularly maintain key components and provide proper lubrication. Select high-rigidity equipment to reduce vibration and stabilize machining quality.

 

(4) Finished Product Inspection

Implement full-process inspection of first piece, in-process, and last piece, adjust process parameters in real time; establish a problem feedback mechanism for continuous process optimization.

 

 

Ruihang Group mainly produces titanium 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