Efficient Machining of Typical Components in the Aerospace Field

In the aerospace industry, rapid developments have led to increasing demands for material performance, resulting in the widespread use of challenging materials such as titanium alloys, high-temperature alloys, and composite materials. For instance, titanium alloys are extensively applied in components like integral disks, engine frames, fan casings, impellers, and landing gear. High-temperature alloys find predominant applications in shafts, disk shafts, turbine disks, combustion liners, ISO S-holes, and more. Composite materials are primarily employed in central wing boxes, vertical tails, wings, and other areas.

These materials represent typical challenging structural components, exhibiting the following typical characteristics:

• Complex internal structures, such as deep internal concave cavities, with non-standard tool shapes, long overhangs, and susceptibility to vibration during machining. The presence of tail-shaped blade root grooves and other poorly accessible concave grooves needs careful consideration in the development of machining programs.

• Thin-walled structures, requiring careful consideration of the impact of cutting forces on the degree of workpiece deformation when selecting tools.

• High dimensional accuracy requirements.

The complexity of aerospace component structures, strict processing requirements, and the difficulty of machining materials pose higher product and service demands on tool companies. Some tool companies, both domestic and international, have provided numerous efficient machining solutions to the industry after years of development.

Machining of Disk Shafts

Machining disk shafts involves two challenging characteristics: deep internal cavities and dovetail grooves. Sandvik Coromant offers reliable solutions to safely accomplish these challenging feature machinings. The use of anti-vibration tool holders with Sandvik Coromant Capto interfaces is recommended. When machining internal cavities up to 150 meters deep, long and slender tools are employed. However, these tools are prone to vibration and require the removal of chips generated during machining from the grooves.

Turbine Disk Machining

Materials for these components, such as Inconel 718, Waspalloy, and Udimet 720, are typically challenging to machine. The challenging features usually include contour machining of cavity profiles while avoiding various interference issues.

ISO S Hole Machining

When processing critical components of aircraft engines, surface integrity is of utmost importance. ISO S hole machining is the final process, making reliability and safety crucial for delivering high-quality parts. Sandvik Coromant provides the following hole machining solutions to meet the requirements of ISO S hole machining effectively.

Landing Gear Machining

Taking aircraft landing gear as an example illustrates the effectiveness of tool improvements in increasing machining efficiency and reducing machining costs. The material of landing gear components is titanium alloy, posing significant machining challenges. Traditional tooling takes approximately one month to process a single part, and due to the difficulty of machining the part, tool wear is very rapid, with the tool's cutting edge lifespan being less than 1 hour. This results in substantial tool consumption and high tool costs for machining such components. In this situation, there is an urgent need to find a tool that can significantly improve machining efficiency, reduce machining costs, or maintain current machining costs.

Vertical Tail Machining

The structure of the vertical tail is shown in Figure 13, and the main challenges in machining such structural components are hole machining and edge trimming.

(1) Hole machining of CFRP: Working conditions and application requirements:

• High fiber content carbon fiber-reinforced composite material, unidirectional tape material.

• Minimal fiber fraying.

• High surface quality and dimensional accuracy.

• CNC machining center.

(2) Working conditions and application requirements:

• Carbon fiber skin.

• Minimal fiber fraying.

• High surface quality: Ra=1.25 µm.

Future tool design and usage should consider the performance match between tool materials and workpiece materials. Tool materials should adapt to the needs of the machining object, especially for the machining requirements of difficult-to-machine materials. Rational tool materials and structural forms should be determined for different workpiece materials and machining conditions. High-speed, efficient, and high-precision cutting requires tools with various excellent properties, where a high-toughness, high-strength matrix + high-hardness, high-wear-resistant cutting edge is the main development direction for future tools.