Sandvik Coromant gives the aerospace industry a greener future, strong!

       OEMs must take a holistic approach to the aircraft of the future.



As one of the world's largest contributors to carbon dioxide emissions, the aerospace industry has an urgent need to provide aircraft that are more environmentally friendly—one that weighs less and can fly longer. However, to achieve this, aluminum and superalloys (HRSA), which are difficult to machine, are required. Here, Sandvik Coromant Aerospace Solutions Manager Sébastien Jaeger explains how aerospace OEMs can sustainably machine these difficult-to-machine parts with the best tooling solutions.



According to the World Economic Forum (WEF): “Achieving net-zero CO2 emissions by 2050 not only contributes to a sustainable green future, but also ensures the financial resilience and competitiveness of the aviation industry as a whole.” The industry’s position is becoming more stable – electric vehicles outsold even diesel vehicles in the UK in August 2021 – but it will take longer for these developments to materialise in aviation.



Overall, the forecast is that electric aircraft will not reach popularity until 2035. According to LonelyPlanet, although easyJet is on track to have an electric plane operating no more than 311 miles (500 kilometers) by 2030 and Norway is aiming to electrify all short-haul flights by 2040, — "In the short term, we won't be flying long distances with rechargeable jumbo jets: the batteries are too heavy."



Electric aircraft are expected to be widely used by 2035.



So, while batteries don't need to lose weight in order to be reused, it is increasingly the responsibility of original equipment manufacturers (OEMs) to make lighter parts to offset this. What we can be sure of is that aluminium – which is stronger in terms of strength, fatigue resistance and other properties – will be used to make these systems lighter.



We will also see expanded applications of new superalloys (HRSAs). In fact, HRSA is already used in aircraft parts that face extreme performance demands, as they remain rigid even in the face of intense heat. The properties of such materials will prove essential, as one of the ways to achieve more sustainable air travel is to make engines burn more powerfully and with more heat.



Production tolerances for parts must also be smaller and designs more diverse. As with electric vehicles, the designs of future electric aircraft—both airframes and engines—by different manufacturers will also be very different from today’s aircraft with internal combustion engines. For the fuselage, some OEMs are exploring triangular shapes, wing-body assemblies, and strut-supported wing concepts. Some other OEMs are sticking to the traditional 'large duct, wing and engine' design.



Engine structures will also come in different forms, such as electric, battery-powered or electromagnetic or hybrid, while today's engines are assisted by electric motors. OEMs will be required to produce a greater variety of small tolerance parts, while also finding new ways to reduce noise, weight and emissions—all factors that affect the performance of an electric system. But aluminum and HRSA parts are difficult to machine, so achieving this in a sustainable and cost-effective manner will be a challenge.



rapid progress



One way to produce lighter, more energy-efficient aircraft is through additive manufacturing (AM) processes. The AM process enables the development of custom parts with extremely complex shapes and functional products with small tolerances, so that difficult-to-machine parts like grilles can be more easily produced. The software company DassaultSystemes found that “in the aerospace industry, weight savings from AM processes can save up to 25 percent,” and that “every kilogram (2.2 pounds) of weight saved on a flight can save up to $3,000 per year in fuel consumption.”



But is the AM process itself sustainable? A study conducted in conjunction with the Department of Manufacturing Engineering at the Technical University of Cluj-Napoca in Romania describes AM as "an excellent alternative to traditional manufacturing (TM) methods such as injection molding, die casting or machining". "AM has the potential to reduce costs and save energy compared to conventional processes," the study said.



AM will also have a crucial impact on how products are made and their diversification. Benefits include reduced carbon emissions, material usage and transportation, as imported parts can be replaced with in-house produced parts.



Manufacturers can also produce more complex, small and innovative aerospace parts through rapid product trial production. Rapid product trial production involves several different processes, but the goal is the same: to rapidly produce a solid 3D prototype model from a computer-aided design (CAD) file. These prototype models enable small trial production of new materials before mass production, ensuring that parts are produced at the highest level of innovation, quality and precision.



We've seen how aerospace OEMs can take new approaches to producing more complex parts. But what if there was the right tool for the job, especially when machining difficult aluminum and HRSA materials?



These materials must use more wear-resistant, longer-life tools. That's why Sandvik Coromant has developed the S205 grade specifically for turning. The S205 material contains a layer of Inveio® crystals that are closely spaced in one direction. This creates a strong protective barrier around the blade, making the tool stronger and more durable and improving its mechanical properties. The blade has proven itself capable of producing a rich array of aircraft parts, including engine turbine disks, rings and shafts. According to Sandvik Coromant customers, S205 offers a 30-50% increase in cutting speed compared to HRSA turning grades.



holistic approach



We've considered the manufacturing process and the tool, but now can we make the best combination of the two? After all, if the individual systems are not designed to fit together and work together, time is wasted trying to compose a fully integrated solution.



To this end, Sandvik Coromant is supporting customers in the aerospace industry with what we call components solutions. The solution consists of several stages, including understanding the machining needs and takt time to understand the cost per part. There is also an analysis of the production method at the final stage, both in relation to MTM (method-time measurement) and end-user processes. Parts solutions also include computer-aided manufacturing (CAM) programming and the management of local or cross-border projects.



Take the example of a Sandvik Coromant customer who was experiencing chip breaking issues during production, and Parts Solutions allowed us to identify the problem and design a solution. Sandvik Coromant's experts developed a new "Dynamic Drive Curve" strategy for this customer, allowing us to control chip breaking at all times. We call this new method "scoopturning" and a patent has been filed for it. With the scoopturning method, the customer reduced cycle times by 80 percent and doubled tool life while maintaining excellent chip control.



In addition, the customer was able to reduce the number of machines it used from four to one, reducing the need for multi-tasking machining while ensuring a more stable and reliable machining process and "green light production." Using fewer machine tools and reducing the number of tool changes (thanks to tougher grades like S205) will be key to more sustainable aircraft production.



Software also plays a vital role, such as CoroPlus® ToolGuide, a digital product from Sandvik Coromant. Customers can make critical decisions on tool and cutting parameter selection even before production begins.



closed loop



In addition to new tooling and manufacturing methods, aerospace OEMs also have access to manufacturing. According to a report by the AirTransport Action Group (ATAG), Kaiser, an aluminum supplier to Boeing, has now adopted a closed-loop recycling system—one of the largest projects of its kind in the industry. Kaiser estimates that through the project, the industry could reuse approximately 10,000,000 kilograms of scrap and scrap metal annually.



At Sandvik Coromant, we have implemented our own recycling system for the recycling of carbide tools, ie: we buy back our customers' discarded carbide tools and remake them into brand new tools. Therefore, most of the raw material used in Sandvik Coromant carbide tools comes from scrap tools. We practice sustainable business in a resource-constrained environment, minimizing excessive waste. As a result, we found that knives made from recycled materials require 70% less energy, while also reducing CO2 emissions by 40%.



The aerospace industry is under increasing pressure to produce greener aircraft that weigh less and fly longer. And aerospace OEMs, with the right machining processes and tools—and of course a more holistic approach to manufacturing—can contribute to a greener future for the aerospace industry.