Aerospace machining with inventive tools and coating

By Staff Report August 30, 2024 4:15 pm IST

Machining aerospace-grade materials like titanium and Inconel requires innovative tools, coatings, and techniques. Advancements in CNC technology, AI, Smart machining, and additive manufacturing are guiding the industry to achieve new levels of precision, efficiency, and performance in producing complex and durable components.

Machining aerospace-grade alloys presents challenges due to their high strength, heat resistance, and hardness. The properties make them difficult to machine, requiring specialised cutting tools, coatings, and techniques. The materials are integral to aerospace applications. They withstand extreme temperatures and maintain structural integrity under high-stress conditions. AI algorithms also optimise cutting parameters based on material properties and tool conditions. Vibration and heat management are also severe challenges in aerospace machining.

Future technologies

Emerging technologies are the result of the industry’s demand for precision, efficiency, and adaptability. There are varying machine tools and cutting tools in the aerospace sector. According to Amit Raina, Country Manager, Dormer Pramet India, CNC machining and cutting tools are evolving to deliver tighter tolerances and multi-functionality, reducing production time and minimising errors. Automation and robotics are propelling factors in this shift. Additive manufacturing is changing aerospace production by enabling complex geometries, rapid prototyping, and lightweight structures while minimising material waste.

Additive manufacturing, or 3D printing, is another game changer. As Amit S Deo, Vice President – Sales and Marketing, Guhring India, notes, additive manufacturing is revolutionising aerospace production by enabling the creation of complex geometries and lightweight structures. It facilitates the direct manufacturing of intricate designs that traditional methods cannot achieve. The development of new materials like high-strength alloys and composites is expanding the applications and performance of 3D-printed aerospace components.

In the aerospace industry, 3D printing creates lighter, more durable, and more fuel-efficient components, thus lowering material costs and shortening production times, ultimately increasing overall efficiency. According to Anil Kumar, Managing Director, Ceratizit India, tools manufactured through 3D printing can provide direct cooling, preventing overheating and ensuring a longer lifespan for the tools.

Advances in materials and coatings, such as nano-coatings and ceramics, improve tool life in harsh conditions like in aerospace applications. Smart machining technologies with sensors and data analytics are becoming essential. Innovations improve productivity, extend tool life, and streamline machining and inspection. As technologies evolve, they create a more efficient, precise, and adaptable future for aerospace manufacturing.

High-speed machining technologies are increasing surface quality for challenging materials like titanium and Inconel, which are widely used in aerospace.

Milling tools for high-speed machining

When choosing the appropriate milling cutter, key aspects to consider are the cutting power and the size of the workpiece to be processed. Zuzer T Lokat, Director of TruCut Precision Tools, highlights additional considerations, such as the material type machined, the volume of stock removal, the required surface finish, and the machine’s capabilities.

Selecting milling tools for high-speed machining requires considering tool material, coatings, and design when selecting milling tools for high-speed aerospace machining. Amit Deo states that coatings reduce friction, improve hardness, and extend tool life. Tools should be optimised for chip removal, with specific flute designs and cutting-edge geometries like high-rake angles enhancing performance. Vineet Seth, Managing Director – South Asia & Middle East, Mastercam APAC, highlights the importance of tools that handle high-strength alloys like titanium and Inconel. Optimised tool geometry ensures efficient chip evacuation and reduces heat buildup. Advanced coatings enhance tool life in demanding conditions, while vibration-dampening properties and compatibility with spindle speeds are essential for optimal performance. These factors are critical for precision and efficiency in aerospace applications. Compatibility with CNC machine parameters and minimising vibrations are crucial.

Amit Raina, Country Manager, Dormer Pramet India, notes that tool grade is critical, with ultra-submicron substrates increasing wear resistance and efficiency. Lower approach angles, larger core diameters, and variable helix designs contribute to performance, stability, and reduced vibrations.

Machining aerospace alloys

Cutting tools are essential in addressing the challenges of machining aerospace-grade alloys such as titanium and Inconel for their strength, heat resistance, and machining difficulty. Vineet Seth, a leading expert, emphasises that tool material selection is crucial when machining these challenging alloys. Tungsten carbide is often the material of choice because of its high hardness, wear resistance, and ability to maintain sharpness at high temperatures. Carbide tools are essential for maintaining precision and resisting deformation under heavy cutting forces, especially when working with titanium and Inconel.

The alloys tend to exhibit work hardening, where the material becomes hard as it is machined, further complicating the process. Aerospace alloys, titanium and Inconel, exhibit characteristics that are challenging for conventional machining processes. Their high strength leads to increased cutting forces, which can cause tool wear.

The cutting tool advancements allow for more efficient machining of aerospace-grade alloys, ensuring high-quality parts that meet the stringent requirements of the aerospace industry.

Tools and coatings

Advanced cutting tool grades for HRSA materials now incorporate carbide bonded with cobalt with rare earth elements known as mixed carbide to extend tool life, mentions Anil Kumar. Ceramic tools hold importance as cutting materials because of their ability to endure the high temperatures and stresses faced in handling the machining of challenging materials.

In addition to carbide tools, ceramic tools made from SiAlON and whisker-reinforced ceramics are gaining traction for machining heat-resistant superalloys like Inconel. These ceramics maintain their integrity at high cutting speeds, making them ideal for aerospace applications. Vineet Seth highlights that ceramic tools offer advantages in removing material efficiently while retaining durability, especially under extreme conditions.

The coatings reduce friction, enhance hardness, and extend tool life, which is critical when machining aerospace materials. Coatings prevent built-up edge formation and improve wear resistance in machining challenging materials like Inconel and titanium alloys. Coatings further enhance tool performance. Coatings incorporating chromium, silicon, and zirconium improve wear resistance and thermal stability. Aluminum Titanium Nitride (AlTiN) and Titanium Aluminum Nitride (TiAlN) are used for coating tools in aerospace applications. AlTiN, known for its hardness and thermal stability, performs well in temperatures up to 1,000°C, making it suitable for high-speed machining. TiAlN offers excellent oxidation resistance and is ideal for high-temperature applications, as noted by Amit Raina.

Keshav Khurana, Executive Director at Wohlhaupter India, points out that coatings have revolutionised cutting tools by providing thermal barriers and increasing surface hardness. These coatings, made from elements like aluminium, titanium, chromium, and silica nitride, improve the lubricity of tools, reduce friction, and eliminate issues like built-up edges. Khurana also stresses that while coatings like TiN, TiCN, and TiAlN are versatile, more material-specific coatings are emerging.

Furthermore, effective cooling and lubrication strategies are equally important. Given the high temperatures, cutting fluids and lubricants must be selected to manage heat and ensure tool longevity.

Machining aerospace-grade alloys like titanium and Inconel requires a strategic combination of advanced tool materials, optimised geometries, and innovative coatings. Amit Raina emphasises the role of advanced coatings in high-temperature machining environments. The aerospace industry continues to strive for performance. The specialised coatings, improved tool designs and advanced cooling strategies stand to overcome the inherent challenges of machining these tough alloys. With ongoing innovations, tool manufacturers and engineers are developing solutions that enhance efficiency, precision, and reliability in the aerospace manufacturing industry.

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Amit Raina, Country Manager, Dormer Pramet India.

Advanced CNC machining and cutting tools are evolving to deliver tighter tolerances and multi-functionality, reducing production time and minimising errors.

Amit S Deo, Vice President – Sales and Marketing, Guhring India.

Additive manufacturing is transforming aerospace production by enabling the creation of complex geometries and lightweight structures.

Vineet Seth, Managing Director – South Asia & Middle East, Mastercam APAC.

Advanced coatings enhance tool life in demanding conditions, while vibration-dampening properties and compatibility with spindle speeds are essential for optimal performance.

Keshav Khurana, Executive Director, Wohlhaupter India Pvt. Ltd.

Coatings have revolutionised cutting tools by providing thermal barriers and improving the lubricity of tools, reducing friction, and eliminating built-up edges.

Zuzer T Lokat, Director, TruCut Precision Tools Pvt Ltd.

As technology advances and manufacturing processes become increasingly sophisticated, the future of the cutting tools industry is getting ready for remarkable transformations.

Anil Kumar, Managing Director, CERATIZIT India Pvt. Ltd.

Advanced technologies are shaping the capabilities of machine tools in the aerospace sector and driving innovation in the design and manufacturing of aerospace components.