Solutions for cost effective and high-quality machining of aerospace landing gear beam
On the fuselage there are several structural components produced in titanium. The landing gear beam is one example of a component with thin floor sections. Machining of structural aerospace components often involve challenging conditions, such as thin floors and walls, deep pockets and tight corners. We help you overcome these challenges with dedicated tools and methods.
Common challenges when machining structural parts:
- Poor productivity
- Vibration
- Deflection of the tool and component
- Short tool life
- Chip jamming
- Time consuming process
CoroMill® MS20 – pocketing
- M-M20 geometry gives higher security in tougher applications
- In case of sensitive / vibration prone applications and / or applications requiring a sharper cutting edge, the E-L50 geometry can be used
- The higher edge line toughness of these geometries allows the inserts to be used with higher productivity (high cutting data) in stable operations
- Robust steel shank design ensures better stability and less deflection. The improved tool body material can withstand chip rubbing better
CoroMill® MH20 – High feed pocketing
When machining deep pockets, especially narrow deep pockets, long overhangs are required. This condition is challenging and there is a high risk of vibrations.CoroMill® MH20 is optimized for pocketing applications in ISO S, M and P materials and ensures secure and vibration-free machining with long overhangs.
CoroMill® Plura HFS - Stable high feed side milling strategy
Tough milling strategies with large tool engagement build up heat and cause excessive cutting forces which is challenging for the tool. A more stable strategy is to program for a large cutting depth (ap) and low cutting width (ae) combined with controlled maximum chip thickness to control the cutting forces. This allows for high feed machining with increased cutting speed and feed to achieve a high metal removal rate.
CoroMill® 316 – Machining thin floors sections
To overcome the thin floor machining challenges, Sandvik Coromant has developed a dedicated machining strategy:
- Spiral morph tool path for maximising part stability to reduce floor deflection
- Optimised remaining stock to achieve finish cut with minimised axial cutting forces
- Corners machined with a slicing method
- Optimised ap/ae relationship to minimise cutting forces and component deflection
Dedicated titanium milling grades
S30T and S40T are available for a variety of CoroMill® cutters for face milling, shoulder milling, long-edge milling, plunging, high-feed milling, profiling and slot milling. Together these grades amount to a new level of reliable long lasting performance.
Grade S30T for speed and tool life
S30T has been developed with productive titanium milling in focus. It combines the properties of micrograin carbide and a wear resistant PVD coating. This enables very sharp cutting edges that resist fatigue and micro-chipping and result in cutting edges that are preserved for longer times in cut at higher cutting speeds.
Grade S40T for difficult conditions
S40T is developed for difficult conditions combining high toughness cemented carbide with a thin CVD coating. The result is a grade that withstands vibration and other difficult cutting conditions for longer times in cut. The wear is predictable, making the cutting edge gradually duller without breaking.
S30T and S40T – Productivity and security in titanium milling
CoroMill® Plura – For finishing of 2D pocket and corner milling - slicing
Perfect choice for finish machining of 2D pockets is the specialized solid carbide end mills. These end mills developed for titanium enables you to machine deep pockets at high metal removal rates without vibration.
Other benefits are high accuracy and long tool life at high cutting data.
CoroMill® Plura and slicing method is the ideal combination when machining corners in titanium components. Multiple passes successively remove material ensuring low radial immersion/engagement angle and low cutting forces.
CoroMill® 300 - Rough face milling
Program a roll into cut in a clockwise motion (counter-clockwise will not solve the thick chip thickness problem). By rolling into cut, the chip thickness on exit is always zero, allowing for higher feed and longer tool life. A round insert cutter provides best productivity and tool life thanks to the lead angle and chip-thinning effect. CoroMill® 300 with S30T and S40T has through coolant and close pitch option, therefore optimized for titanium. Now available in insert sizes up to 20 mm (metric) or 1.0’’ (inch).
CoroMill® 690 - 2D profile milling
For this operation we can provide a total solution from roughing through to finishing. The best choice for roughing is CoroMill® 690 with specialized titanium grades S30T and S40T. The axial location of the inserts is built into the bottom of the insert to prevent movement and enable high metal removal rates with security. Its design makes it cut light and use minimum power. Each coolant hole is threaded to allow smaller diameter nozzles for high pressure coolant applications.
Roughing of 2D pocket - Solution 1
For roughing of the 2D pocket, apply the circular ramping method using low depths of cut but up to 1.0 mm feed per tooth together with the high feed cutter CoroMill® 210 or CoroMill® MH20. These tools provide a light and fast technique with excellent metal removal rate and are suitable for all machine concepts and configurations.
The advantages with this circular ramping method are reduced number of tools (no drills needed) and flexibility – can produce a wide range of sizes. Alternative tools using the same programming technique are round insert cutters such as CoroMill® 300.
Roughing of 2D pocket -Solution 2
Opening up a 2D pocket with spiral morphing method using the CoroMill 390 long edge with 11 mm size insert and new titanium grade S30T provides excellent metal removal rates. Keep arc of engagement low when pocketing - produce a large entering hole (made by either drilling or helical ramping), roll into cut, then program with large corner radii to avoid vibration in corners.
High pressure coolant
The recommendation here is simple, always apply coolant when cutting titanium in large amounts and if possible at high pressure. Using high pressure coolant for milling in titanium will double the tool life compared to normal coolant pressure. The critical re-cutting of chips that damages the tool is prevented as welded chips are blown off.
Recommendations:
- Apply coolant through spindle and tool
- Volume and pressure should be carefully planned in relation to the number and diameter of coolant holes and your operation
- Nozzle sizes should be kept small to maximize pressure
- Recommended pressure: 70 bars or more
- Recommended volume: 50 litres/minute
CoroChuck™ 930
Thanks to its excellent clamping performance this chuck offers the best pull-out security on the market, for excellent stability and accessibility in milling and drilling operations. A solution that doesn’t just helps increase machining safety and precision, but also increases production efficiency through quick and easy tool set-ups and changes. For 100% pull-out prevention, a collet with mechanical locking interface is available for Weldon shanks.
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