一、 Clamp and support to prevent deformation
1. Special fixture design
To avoid excessive local stress: use a fully enclosed jacket or imitation fixture to increase the contact area.
Slender shaft processing: Use an adaptive spindle to support the inner hole, and use double top tip clamping to counteract bending caused by radial forces.
2. Auxiliary support
Thin walled or weakly rigid parts: Add auxiliary brackets to enhance the rigidity of the system.
二、 Tool selection and parameter optimization
1. Tool material
Prioritize using YG8 hard alloy, ceramic coated cutting tools, or cubic boron nitride to avoid coatings with high titanium affinity.
2. Geometric parameters
The front angle should be small, and the blunt radius of the cutting edge should be ≤ 0.02mm to reduce sticking and chip accumulation.
三、 Cooling and chip removal control
1. Coolant selection: Hydrogen containing cutting fluid is prohibited, and extreme pressure emulsion or high-pressure mist cooling is used.
2. Chip removal strategy
Deep hole machining: using a spiral reamer with frequent chip removal to prevent chip blockage and scratching of the hole wall.
Maintain reverse milling during milling to reduce chip sticking.
四、 Process route design
1. Necessity of preprocessing
Annealing treatment: eliminates residual stress in the material and reduces the tendency for work hardening.
2. Optimization of processing sequence
First rough, then fine, first inside, then outside: leave a margin of 0.5mm for rough machining, and perform aging treatment to stabilize the size before fine machining.
Alternative process: For deep holes, wire cutting is used instead of drilling and boring to avoid deformation of the outlet horn mouth; Turning the outer circle to milling the hinge hole reduces vibration.
五、 Deformation and Quality Control
1. Staged processing: Long axis type: segmented cutting, cross directional processing, compensating for elastic rebound.
2. Real time monitoring: During the precision machining stage, every 2-3 pieces are checked for size, and online measuring instruments are used to compensate for tool errors.
3. Surface treatment: Shot peening: enhances fatigue strength and suppresses the propagation of surface microcracks.
Key tip: The machining of titanium alloy shafts requires full control of cutting temperature, avoidance of contact with copper/zinc fixtures, and thorough cleaning of surface grease between processes to prevent stress corrosion. The process parameters need to be dynamically adjusted according to the shaft diameter ratio, and it is recommended to use vibration suppression devices for high aspect ratio workpieces.