Future trends in aerospace

For decades, aerospace has been an industry characterized by growth. There have been crises over the years, but never one so deep and heavy as COVID-19. Now that the markets have returned to levels of growth last seen in 2006, how can aerospace manufacturers get back on track? The answer lies in more sustainable manufacturing. Here, Sébastien Jaeger, Industry Solution Manager – Aerospace for cutting tools specialist Sandvik Coromant, explains how collaboration will play a vital role in the recovery of the aerospace industry.

The aerospace industry had experienced consistent growth for 14 years when the pandemic struck. There’s no doubt that trends and the future of aerospace have been hugely affected by the unprecedented pandemic. Business and vacation travel have seen an exponential reduction, while airlines have had to adjust to substantially lower levels of profitability.

Yet it isn’t all bad news. The aerospace sector saw some improvement in the first half of 2021; however success is tied to several factors including vaccination and the global economic outlook, with Chinese economic prosperity, business and holiday travel recovery also exerting an influence. Projections estimate the industry will be back to where it was – pre-crisis – within the next two-to-three years. The speed of this recovery will vary in different countries and regions. Nevertheless, over the long-term, the number of new aircraft could still see a decrease of 25% by 2040.

Manufacturers are taking varied design approaches to tomorrow’s electrified aircraft, including Airbus Group’s Airbus E-Fan prototype.

Another big change from an engineering perspective is that aircraft will be single-aisled rather than twin-aisled, and therefore less wide-bodied. They will also need to have a longer flying range. Engines and frames are closely connected, but with engines, the focus is on sustainability. This means reduced weight, noise and emissions and higher efficiency with lower consumption. These single-aisled craft must be suitable for a wide range of applications, without increasing the size or number of engines.

There are different ways of approaching these design challenges. One is to find alternative fuels using existing engine tanks, such as synthetic fuel, biofuel or hydrogen. Another is the longer-term approach of new engine architecture, with large manufacturers introducing brand new engine types. Alternative engine types such as electrified, battery-driven or electromagnetic, as well as hybrid engines (conventional engines assisted by electric motors), are a further option.

Challenging materials

If we look at the automotive industry, it is already making great progress with new electrified and hybrid systems. Aerospace original equipment manufacturers (OEMs), meanwhile, are still working on these systems, and many of these developments are not expected to find widespread use before 2035. With smaller aircraft, which hold between two and ten people, for example, these technologies could appear earlier.

Reductions in noise, weight and emissions will of course affect how these electric systems perform, but there are challenges. If there are issues in an automobile-type electric vehicle (EV), it can stop at the side of the road — that’s not an option 10000 feet up in the air. What’s more, batteries become heavier when designers and engineers want planes that are lighter and that travel longer distances. So, there are technical obstacles to overcome.

For components such as the aircraft’s fuselage, OEMs are heading in two different directions. On the one hand, we are seeing increased use of aluminum, although aircraft components require new types of aluminum with greater strength, fatigue resistance and other properties. This approach fits with traditional aircraft designs, which – to put it simply – comprise a big tube with wings and engines.

Another approach is to explore different aircraft shapes, such as the delta shape, blended wing body and strut braced wing, or shapes in which the engines are better integrated into the fuselage. In this case, engineers are more likely to use composite, or composite-ceramic combinations and mixed materials. Whether these designs become popular remains to be seen. For now, we can be sure that more aluminum will be used, as well as heat-resistant super alloys (HRSAs). HRSAs are typically used for aircraft parts that face extreme performance demands. Their high strength at elevated temperatures means the materials can retain their hardness when subjected to intense heat.

However, even the best aircraft component manufacturers can be inexperienced in manufacturing these tougher materials. This is where Sandvik Coromant’s expertise has proved useful.

Component solutions

Sandvik Coromant offers component solutions in response to the growing pressure on machinists to multi-task. Rather than focus on a single machine, today’s engineers can operate four or five machines at a time, which gives them less time and opportunities to focus on specific processes. But what do we mean by a component solution? This approach adopts a more holistic perspective, which means it’s not just about the tools Sandvik Coromant provides, but also about assisting the process as a whole.

Such was the case when a Sandvik Coromant aerospace customer was experiencing challenges with machining HRSA materials. The customer’s existing approach required multiple machine tools, with poor chip control and long cycle times. There were issues with inconsistent tool life and unreliable processes, and the machining operation often required full-time monitoring by an operator.

For high-value projects such as these, the Sandvik Coromant component solution comprises several stages. They include looking at the machine requirements, time studies to examine the cost per component, and analyzing production methods at the run-off related both to Methods-Time Measurement (MTM) and end-user processes. Other stages include computer-aided manufacturing (CAM) programming and project management of local or cross-border projects.

These analyses revealed that we needed to change the customer’s programming strategy to solve its chip breaking problems. In combination with the tool, Sandvik Coromant’s specialists developed a new strategy with dynamic drive curves, which gave us permanent control of chip breaking. We called this new approach scoop turning and have since patented it.

Scoop turning resulted in excellent savings for the customer. In addition to great chip control, the customer also achieved an 80% reduction in cycle time and a doubled tool life. It was able to reduce its use from four machines down to one, decreasing the need for multi-tasking with more secure machining processes and green light production.

This shows how a more holistic approach can benefit a manufacturer’s bottom line. Software also plays a vital role, for example CoroPlus® Tool Guide, which is part of Sandvik Coromant’s digital portfolio. Customers can make crucial decisions on the choice of tool and cutting parameters before they have even started production.

More sustainable turning

Aerospace manufacturers are taking different approaches to tackling sustainability. Nevertheless, Sandvik Coromant found it is possible to develop a bespoke solution for one customer that has since benefited entire industries.

To help the customer perform better turning operations on HRSAs, Sandvik Coromant’s response was to develop the S205 turning grade. The insert is coated with a second generation Inveio® coating for high wear resistance and long tool life, while post-treatment technology strengthens the S205 insert by altering its mechanical properties. The material has an Inveio® layer characterized by tightly packed, unidirectional crystals which create a strong protective barrier around the insert. This maximizes thermal protection and improves crater wear, while offering better flank wear resistance.

The grade is well suited for machining components such as aircraft engine turbine disks, rings and shafts. Our customers have reported 30 to 50% higher cutting speeds with S205 compared with competing HRSA turning grades, and these results were achieved without compromising the tool life. S205 has since benefited several manufacturers in aerospace and other industries. These results were achieved with a holistic approach, specifically using Sandvik Coromant’s PrimeTurning™ ethos, which allows all-directional turning for maximized productivity.

The PrimeTurning™ methodology is based on the tool entering the component at the chuck and removing material as it travels towards the end of the component. This prioritizes all-important metal removal rates for faster, quality production and changeovers. In some cases, our customers have completed production runs with just one tool changeover when, using a competitor’s tool, they would have needed five.

Aerospace may be facing one of its biggest crises yet, but there is light behind the clouds. Sandvik Coromant continues to support all the leading aerospace OEMs in their post-pandemic recovery, marrying sustainability with better tools and optimized cutting parameters with a holistic approach to tooling.