New Cr-Mo-Si Alloy Could Rewrite Jet Engine Heat Limits

Researchers have developed a new material with remarkably high temperature resistance, demonstrating strong potential for use in jet engines.

Powerful technologies like jet engines, gas turbines, industrial machinery, and X-ray equipment require materials that can withstand extremely high temperatures. Refractory metals like tungsten (W), chromium (Cr), and molybdenum (Mo), with extremely high melting points of around 2,000 degrees Celsius or higher and exceptional resistance to heat, wear, and deformation, are ideal for such applications.

However, while these metals show impressive thermal stability, they become very brittle at room temperature. These metals also oxidize rapidly when exposed to oxygen, leading to material failure at temperatures between 600 and 700 degrees Celsius.

As a result, these materials can only be used effectively under complex vacuum conditions, such as in X-ray rotating anodes. To overcome these limitations, engineers have long relied on nickel-based superalloys to build components that must withstand high heat.

Nickel-Based Superalloys: Strengths, Limits, and Why They’re Maxing Out

A superalloy is a high-performance alloy known for its exceptional mechanical properties and resistance to extreme heat and high stress. They also have good surface and phase stability, and high oxidation and corrosion resistance.

These alloys were initially developed for aircraft turbine engines, only to expand to many other demanding applications over time, including gas turbines, rocket engines, power generation, chemical processing, and petroleum plants. 

They are primarily based on nickel, iron, or cobalt and can maintain mechanical integrity at temperatures where most other alloys would fail. 

Nickel (Ni) is of key importance here. The silvery-white, lustrous transition metal is known for its use in stainless steel alloys. It actually plays an important role in battery energy density and performance, enabling longer-range capabilities in electric vehicles. 

The metal’s properties are also critical for aerospace components, which are exposed to temperature variations and humidity. Being resistant to oxidation and corrosion, nickel alloys extend the lifespan of components, thus enhancing operational efficiency and safety.

Nickel-based superalloys are actually most widely used for the hottest parts, making up over 50% of the weight of advanced aircraft engines, thanks to their outstanding resistance against creep and stress rupture at high temperature.

They also exhibit high-temperature strength, resistance to fatigue, lightweight durability, and good electrical conductivity.

These multi-component alloys consist of nickel and may include alloying elements like aluminum (Al), chromium (Cr), cobalt (Co), titanium (Ti), and molybdenum (Mo) to enhance their properties.

Nickel-based superalloys have their own limitations, though, including high cost, difficulty in machining due to work hardening and low thermal conductivity, and susceptibility to cracking during welding and additive manufacturing. They can also suffer from oxidation and can experience degraded mechanical properties due to the formation of undesirable precipitates.

“The existing superalloys are made of many different metallic elements, including rarely available ones, so that they combine several properties. They are ductile at room temperature, stable at high temperatures, and resistant to oxidation.”

– Professor Martin Heilmaier from KIT’s Institute for Applied Materials, Materials Science and Engineering

But the issue is their operating temperatures, which are “the temperatures in which they can be used safely,” and they range up to 1,100 degrees Celsius. He added:

“This is too low to exploit the full potential for more efficiency in turbines or other high-temperature applications. The fact is that the efficiency in combustion processes increases with temperature.” 

To remove these limitations, the German Research Foundation (DFG) provided funding, and the researchers successfully developed¹ a new alloy of chromium (Cr), molybdenum (Mo), and silicon (Si).

Click here to learn about the hyperadaptor alloy engineered for extreme industrial demands.

Cr-Mo-Si Refractory Alloy: Room-Temp Ductility + 1,100 °C Oxidation Resistance

While cars and trucks are rapidly being electrified to achieve sustainable transport and decarbonize the sector, combustion engines in long-range aircraft will still be needed, at least in the coming decades.

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Electricity-powered airplanes, Heilmaier noted, “will hardly be suitable for long-haul flights in the next decades. Thus, a significant reduction of the fuel consumption will be a vital issue.”

In a turbine, a just 100 degrees Celsius increase in temperature can reduce fuel consumption by about 5%. 

So, one way to improve the efficiency of energy conversion from fossil or synthetic fuels is to increase their operating temperatures. But to achieve that, single-crystalline nickel-based superalloys need to be replaced by refractory materials in the hottest areas of turbines, which display much higher solidus temperatures beyond 2,000 °C.

The replacement of advanced Ni-based superalloys by new metallic-intermetallic materials, however, is hindered by two primary limitations. This includes a lack of oxidation resistance and/or ductility at room temperature (RT). 

The thing is that ductility and oxidation resistance cannot be predicted sufficiently to enable targeted material design. 

Currently, there are no accurate predictive simulation capabilities for either of the two properties. This is despite the significant progress made in the computer-assisted development of materials. As a result, scientists and engineers must depend on observations.

Published in Nature, the latest study titled ‘A ductile chromium-molybdenum alloy resistant to high-temperature oxidation‘ introduced the new material: a single-phase Cr-36.1Mo-3Si alloy.

The refractory metal-based alloy “is ductile at room temperature, its melting point is as high as about 2,000 degrees Celsius, and – unlike refractory alloys known to date – it oxidizes only slowly, even in the critical temperature range,” said Dr. Alexander Kauffmann, a professor at the Ruhr University Bochum, who played a major role in this discovery.

The use of Cr and Mo here addresses the problems of refractory metal elements, showing problems in oxidation, which limit their application. While Cr leads to the formation of a protective Cr2O3 scale, Mo makes the regions resistant to nitridation. 

Si is used as a minor third element to ensure slow growth of the Cr2O3 scale. Its low amount enabled the researchers to synthesize single-phase, disordered solid solutions.

With its unparalleled properties, “this nurtures the vision of being able to make components suitable for operating temperatures substantially higher than 1,100 degrees Celsius. Thus, the result of our research has the potential to enable a real technological leap,” Kauffmann said.

But while the material meets the most important critical requirements for refractory materials, for it to be used on an industrial level, it has to go through “many other development steps.”

Still, “with our discovery in fundamental research, we have reached an important milestone. Research groups all over the world can now build on this achievement,” Heilmaier said.

Who’s Leading the Materials Race: U.S., Europe, China, Turkey

As researchers continue to break the temperature and durability barriers of traditional nickel-based superalloys, similar breakthroughs are taking shape around the world.

Earlier this year, a team at Ames National Laboratory discovered a new alloy to potentially replace nickel- and cobalt-based superalloys,whose heat tolerance limits improvement in energy efficiency.

They also naturally turned to refractory metals because they are the only ones with melting points much higher than those of nickel and cobalt. But of course, there’s the complex matter of manufacturing and shaping them into parts.

So, the researchers decided to combine refractory metals into multi-principal-element alloys, which are not based on a single element but on three or more elements, with none exceeding 50% of the overall composition.

“We’ve come to understand that combining many of these otherwise brittle pure elements in significant amounts creates atomic structures that have emergent, unique properties.”

– Team lead Nicholas Argibay, who’s a scientist at Ames Lab, a U.S. Department of Energy Office of Science National Laboratory operated by Iowa State University. 

However, mixing more than three elements together means “millions of combinations to search for,” which is a time-consuming process. But thanks to AI, they were able to save time and money and “get it right” on the first shot

So, to find the materials and their composition, the researchers utilized a computational framework, which was developed by two Ames Lab scientists, Prashant Singh and Duane Johnson.

“We put together a theory-guided methodology that interfaces with experiments. It points the experimentalists in the right direction for new alloys with the specific properties that they want to have in those materials.”

– Johnson

This new alloy exhibits more resilience to deformation at higher temperatures and the necessary ductility properties to be manufactured using commercially established methods. 

The Ames team’s approach highlights how data-driven design can accelerate discoveries that once took years of trial and error. Building on this collaboration between computation and experimentation, researchers at MIT merged machine learning (ML) with metal 3D printing² design an Al-based alloy whose printed parts match the strength of wrought 7075—and, after 400 °C aging, are ~50% stronger than the strongest printable Al benchmark. 

To create this new metal, the team mixed aluminum with other elements identified through simulations and ML.

The researchers hope to have their new printable metal made into stronger, more lightweight, and temperature-resistant products, such as fan blades in jet engines, which are made with costlier and heavier titanium.

“If we can use lighter, high-strength material, this would save a considerable amount of energy for the transportation industry,” said the study lead Mohadeseh Taheri-Mousavi, who’s now an assistant professor at Carnegie Mellon University.

Besides the aerospace and transport industry, the researchers envision their printable alloy to be used in cooling devices for data centers and high-end automobiles. Their work emphasises how additive manufacturing and AI-driven alloy design are meeting to create lighter, stronger, and more thermally efficient materials, properties essential for future jet propulsion and energy systems.

In another part of the world, Turkish aerospace motor manufacturer TEI has reported developing over 20 unique superalloys and titanium alloys for use in fighter jet and helicopter motor technology.

“Wars are now won in laboratories and factories. The technology you produce determines the fate of war.”

– TEI General Manager Mahmut Faruk Aksit

With temperatures inside aircraft engines reaching extremely high, ‘half the temperature of the sun’s surface,” it requires metals that can operate in such extreme heat. This makes  “cooling systems, special coatings and material technologies are critically important,” he added.

Similar momentum is unfolding in China, where researchers are currently working on a new superalloy cooling technique to improve the performance and durability of high-temperature turbine engine components, which can enable advanced jet engines.

Chinese researchers have also created a new technique to produce alloy turbine blades that can withstand temperatures up to 15% higher than existing versions. This enhanced heat resistance is expected to deliver greater engine thrust, better energy efficiency, and longer life.

“This method embeds a copper-magnesium-steel composite structure inside the blade using thermo-mechanical processing techniques,” states the patent for the tech. “This enables the blade to maintain long-term functionality under extreme high-temperature conditions.”

The use of copper’s thermal conductivity and steel’s heat resistance makes the composite suitable for future applications in aircraft and rocket engine combustion chambers. So, this is how scientists around the world are working on improving various aspects of jet engines, helping revolutionize aviation and power generation.

Click here to learn how an enhanced banocrystalline alloy could revolutionize the aerospace & auto sectors.

Investing in Jet Engine Advancement 

Aerospace and defense company, Raytheon Technologies (RTX -0.52%), is one of the leading global investors in advanced materials and propulsion innovation through its subsidiary Pratt & Whitney. This segment supplies aircraft engines for military, business jet, commercial, and general aviation customers.

It has two other segments: Collins Aerospace provides technologically advanced aerospace and defense products and aftermarket service solutions, and Raytheon develops advanced capabilities in air and missile defense, smart weapons, and others.

The company regularly funds and collaborates with academic and government research initiatives in pursuit of higher-efficiency, higher-temperature materials for next-generation jet engines. It is exploring refractory alloys, ceramic matrix composites (CMCs), and additive manufacturing techniques. 

With a market cap of $239.5 billion, RTX is currently trading at $178.75, up 54.38% this year so far. Just last week, RTX shares hit an all-time high (ATH) of $180.50. Just two years ago, the company’s stock prices were trading under $100.

It has an EPS (TTM) of 4.87 and a P/E (TTM) of 36.68. The dividend yield offered to shareholders is 1.52%.

When it comes to the company’s financials, RTX reported sales of $22.5 billion for the third quarter of 2025, an increase of 12% from the prior year. 

Pratt & Whitney segment posted an operating profit of $751 million, up 35% and $8.42 billion in adjusted sales, up 16% versus the prior year. This growth in sales was led by a 23% increase in commercial aftermarket, which was driven by higher volume in both large commercial engines and Pratt Canada, a 15% jump in military was due to the F135 program, and a 5% increase in commercial OE as a result of increased large commercial engines volume.

Meanwhile, its avionics and other aircraft systems supplier Collins Aerospace saw revenue increase by 8% to $7.62 billion, with growth coming from military sales, original equipment for new jets, and airlines purchasing repairs and more parts. Raytheon’s revenue jumped 10% to $7.05 billion as demand for both its air defense systems and naval programs remained strong.

The company’s GAAP EPS was $1.41, and adjusted EPS was $1.70. Operating cash flow for the quarter was $4.6 billion, and free cash flow was $4 billion. It also reported a backlog of $251 billion, which included $148 billion in commercial and $103 billion in defense.

“Strong execution in the third quarter enabled us to deliver double-digit organic sales growth across all three segments and our sixth consecutive quarter of year-over-year adjusted segment margin expansion,” said CEO Chris Calio. “We also received $37 billion of new awards in the quarter, reflecting robust global demand for our products and supporting long-term growth for RTX.”

RTX paid down $2.9 billion of debt in the third quarter and returned $900 million to shareholders.

Based on this performance and “ongoing demand strength,” the company raised its full-year outlook while noting its commitment to “executing on our $251 billion backlog and increasing our output to support the ramp across critical programs, while investing in next-generation products and services that meet the needs of our customers.“

Latest Raytheon Technologies (RTX) Stock News and Developments

Conclusion

High-temperature alloys play a vital role in materials science and energy technology. The world’s push toward efficiency and sustainability means we need materials that can handle extreme conditions, and that demand is only increasing.

For decades, nickel-based superalloys have been the standard choice for turbine and jet engine parts. But they’re hitting their limits. That’s why the recent discovery of a ductile, oxidation-resistant Cr-Mo-Si alloy is generating excitement. If researchers can develop and scale up production, these next-generation refractory alloys might revolutionize aerospace, letting jet engines run at temperatures well beyond what’s possible today. The potential applications don’t stop there, as this might open doors to energy production, industrial heating, and even space propulsion.

Of course, getting from laboratory discovery to commercial reality is never simple. Scientists will need to fine-tune the alloy’s composition, work out manufacturing challenges, and develop ways to produce it in large quantities. But even with those hurdles ahead, this breakthrough opens up promising new possibilities for high-temperature engineering.

Click here to learn all about investing in titanium.

References

1. Hinrichs, F., Winkens, G., Kramer, L. K., Falcão, G., Hahn, E. M., Schliephake, D., Eusterholz, M. K., Sen, S., Galetz, M. C., Inui, H., Kauffmann, A., & Heilmaier, M. (2025). A ductile chromium–molybdenum alloy resistant to high-temperature oxidation. Nature, 646, 331–337. https://doi.org/10.1038/s41586-025-09516-8
2. Taheri-Mousavi, S. M., Xu, M., Hengsbach, F., Houser, C., Ge, Z., Glaser, B., Wei, S., Schaper, M., LeBeau, J. M., Olson, G. B., & Hart, A. J. (2025). Additively Manufacturable High-Strength Aluminum Alloys with Coarsening-Resistant Microstructures Achieved via Rapid Solidification. Advanced Materials. https://doi.org/10.1002/adma.202509507