Ceramics reach new heights
The field of aerospace and space technology is rarely out of the news, and with ceramics finding increasing application in these industries, the free-to-attend Ceramics Expo is set to welcome more C-level executives, R&D specialists, component designers, and production managers from these industries than ever before. Recent forecasts are for overall growth levels in excess of five per cent for the years ahead, and technical ceramics will surely play a key role in ensuring that the next generation of systems are lighter, more efficient, more durable, cost-effective, and safe.
Fantastic opportunities exist for ceramics in rapidly expanding areas – for example, the use of ceramic matrix composites (CMCs) in additive manufacturing. It is predicted that the global market for AM in aerospace will top $3 billion as soon as 2022, with North America leading the way.
GE Aviation has been active in utilizing AM, especially with its unique (for North America) silicon carbide facilities, while Rolls-Royce is introducing CMCs in its future engine programs. The Rolls-Royce Advance3 engine is helping pioneer the future of civil aerospace and its technology demonstrator engine is providing both technology and a new core for the company’s UltraFan engine design that will be available from 2025 and will offer a 25 per cent improvement in fuel efficiency compared with a first-generation Trent engine. In February this year, Safran inaugurated its advanced turbine blades research center, deploying its proven expertize, along with innovative technologies such as multidisciplinary design, single-crystal casting, 3D-printed ceramic cores, thermal coatings, cooling circuits, digitized processes, self-adapting micro-drilling, non-destructive testing based on artificial intelligence, and more.
Over the years, products from Ceramics Expo exhibitors have proved invaluable to the aerospace sector. A pioneer of aerospace material solutions, Morgan Advanced Materials developed Min-K, an AS 9100-certified material. Min-K engineered solutions provide exceptional thermal insulation and fire-protection properties. These microporous solutions are available as board, rigid panel, and flexible compositions that are capable of being machined or fabricated with various facing and encapsulations from textiles to alloys. Min-K offers high-performance solutions for the most challenging applications and awkward spaces, while also being very lightweight with high compressive strength and good resistance to vibration. It also boasts exceptional thermal efficiency and low shrinkage at high temperatures.
The benefits offered to space and aerospace by ceramics, glass, and associated technologies are also ably demonstrated by international player Johnson Matthey, another Ceramics Expo exhibitor. Its specially developed products include strong and rigid platinum and palladium pinning wire that holds ceramic cores within the turbine blade during casting; iridium and platinum components for premium aerospace spark plug producers; ultra-fine precious metal wire and thermocouple wire that can withstand harsh environments while maintaining excellent control, accuracy, and reliability; and Platinum Q SALT, a market-leading electroplating bath suitable for use in the electroplating of turbine blades used in aerospace engines and industrial gas turbines.
Elsewhere, CoorsTek – a stalwart of Ceramics Expo from day one – has made a major announcement that will keep it in line with all the ambitions and demands of the aerospace industry: it is beginning groundbreaking activities for a new facility expansion in Benton, Arkansas. The expansion has attracted $26 million in capital investments and will increase the company’s workforce by more than 15 per cent.
The combination of high precision and great flexibility is a winning one when it comes to exploiting ceramic materials in space programs. Just recently, finely detailed ceramic parts have been 3D printed using simulated lunar regolith as part of an investigation led by the European Space Agency (ESA). “These parts have the finest print resolution ever achieved with objects made of regolith simulant, demonstrating a high level of print precision and widening the range of uses such items could be put to,” commented ESA materials engineer Advenit Makaya. “If one needs to print tools or machinery parts to replace broken parts on a lunar base, precision in the dimensions and shape of the printed items will be vital.” The technology partner for this successful enterprise was Ceramics Expo exhibitor Lithoz, whose CEO Johannes Loma said: “Thanks to our expertize in the additive manufacturing of ceramics, we were able to achieve these results very quickly. We believe there’s huge potential in ceramic additive manufacturing for the Moon.”
Newly developed ceramic aerogel resting on a flower
Meanwhile, researchers from the University of California and collaborators at eight other research institutions have created a new ceramic aerogel that is so lightweight it can rest on a flower without damaging it. The material could be used for applications such as insulating spacecraft because it can withstand the intense heat and severe temperature changes that space missions endure. The material is made of thin layers of boron nitride, a ceramic with atoms that are connected in hexagonal patterns, and can be compressed to five per cent of its original volume and fully recover. Lead researcher Xiangfeng Duan explained, “The key to the durability of our new ceramic aerogel is its unique architecture. Its innate flexibility helps it take the pounding from extreme heat and temperature shocks that would cause other ceramic aerogels to fail.”
Of course, space isn’t all about intense heat. “Space is cold,” says glass-ceramic specialist SCHOTT. “It is not, however, a uniform temperature. Satellites and space-based telescopes regularly pass through the shadows of the Earth or the Moon, and this causes slight temperature variations which can distort the shape of materials. For space-based telescopes and satellites that require intense precision, the temperature fluctuations create tiny distortions that make either instrument less accurate.”
SCHOTT ZERODUR glass-ceramic consists of a crystalline and a residual glass phase, which together enable extremely low coefficients of thermal expansion nearing zero. The thermal expansion is also highly homogeneous. Even with large material components, fluctuations in mechanical and thermal properties are hardly detectable, making ZERODUR ideal for optical applications with special demands on precision and temperature stability. These characteristics have made ZERODUR a top choice for the mirror substrate in space-based instruments, including in the European Southern Observatory’s Extremely Large Telescope.
Learn more about ceramic applications for the aerospace industry at Ceramics Expo 2019.