Aerospace composite materials for high speed Aircraft and Missile applications

Rajesh Uppal January 15, 2023 Air Force, Material Comments Off on Aerospace composite materials for high speed Aircraft and Missile applications 374 Views

Since the birth of aviation, designers have continuously endeavored to improve the lift-to-weight ratios of aircraft. With increasing fuel costs, commercial aerospace manufacturers are under pressure to enhance the performance of aircraft, for which weight reduction is a key factor.

Military forces around the world prefer lightweight aircraft, which provide fuel efficiency and higher strength. Defense aircraft materials are lightweight materials known to deliver high performance. They are selected depending on various properties such as strength, thermal shock resistance or expansion, resistance, flammability, stealth, and fuel efficiency.

Further, the structure has to meet the requirements of fuel sealing and provide access for easy maintenance of equipment. Passenger carriage requires safety standards to be followed and these put special demands of fire retardance and crash-worthiness on the materials and design used. For spacecraft the space environment–vacuum, radiation, and thermal cycling–has to be considered and specially developed materials are required for durability

The different types of materials used in defense aircrafts are aluminum alloys, super alloys, steel alloys, composite materials, and titanium alloys among others. A modern military aircraft is composed of several metal alloys and composite structures joined to create the specific structural profile of airframe and other constituent parts and components that fulfill the specified operational requirements of the aircraft.

Composite materials have played a major role in weight reduction, and hence they are used for both structural applications and components of all spacecraft and aircraft from gliders and hot air balloon gondolas to fighter planes, space shuttle and passenger airliners.

Composites are essential materials made up of 2 or more phases or constituent parts, predominantly plastics reinforced with carbon fibers. Better known man-made composite materials, used in the aerospace and other industries, are carbon- and glass-fiber-reinforced plastic (CFRP and GFRP respectively) that consist of carbon and glass fibres, both of which are stiff and strong (for their density), but brittle, in a polymer matrix, which is tough but neither particularly stiff nor strong. Very simplistically, by combining materials with complementary properties in this way, a composite material with most or all of the benefits (high strength, stiffness, toughness and low density) is obtained with few or none of the weaknesses of the individual component materials. They can be formed into various shapes to increase their strength and layered with fibers running in different directions, to allow designers to form structures with unique properties.

CFRP and GFRP are fibrous composite materials; another category of composite materials is particulate composites. Metal matrix composites (MMC) that are currently being developed for the aviation and aerospace industry are examples of particulate composites and consist, usually, of non-metallic particles in a metallic matrix; for instance silicon carbide particles combined with aluminium alloy.

There is large-scale use of advanced composites in current programmes of development of military fighter aircraft, small and big civil transport aircraft, helicopters, satellites, launch vehicles and missiles all around the world. The emergence of strong and stiff reinforcements like carbon fibre along with advances in polymer research to produce high-performance resins as matrix materials have helped meet the challenges posed by the complex designs of modern aircraft.

The current generation military aircraft have about one-third of the structural weight of the aircraft built in advanced fibre-reinforced polymer composites which includes such critical and primary structures as wing, fin, control surfaces and radome. On the other hand, small all-composite aircraft has been on the anvil for some time. These non-metallic materials compete favourably with advanced metallic materials such as new and improved alloys of A1-Li, AI-Cu, AI-Zn and Ti.

The composites-in particular, the advanced fibre reinforced composites using carbon or aramid fibres in polymer matrices–offer several of these features as given below:
• Light-weight due to high specific strength and stiffness;
• Fatigue-resistance and corrosion resistance;
• Capability for high-degree of optimization: tailoring the directional strength and stiffness;
• Capability to mould large complex shapes in small cycle time reducing part count and assembly times.
Good for thin-walled or generously curved construction;
• Capability to maintain dimensional and alignment stability in space environment;
• Possibility of low dielectric loss in radar transparency;
• Possibility of achieving low radar cross section.

These composite materials also have some inherent weaknesses:
• Laminated structure with weak interfaces: poor resistance to out-of-plane tensile loads;
• Susceptibility to impact damage and strong possibility of internal damage going unnoticed;

• Moisture absorption and consequent degradation of high-temperature performance;
• Multiplicity of possible manufacturing defects and variability in material properties.

Composite Market

The global aerospace composites market size is expected to grow from $23.03 billion in 2021 to $25.79 billion in 2022 at a compound annual growth rate (CAGR) of 11.98%. The global aerospace composite market size is expected to grow to $43.33 billion in 2026 at a CAGR of 13.84%.

The global high-speed aircraft and missiles composite material market was valued to be at $1,631.9 million in 2021, which is expected to grow with a CAGR of 2.47% during the forecast period 2022-2032 and reach $2,083.0 million by 2032.

Rising growth of aerospace composites applications in commercial and military aircraft, to meet lightweight and sturdy component requirements will boost the overall market growth. Factors including weight reduction and high impact resistance will support the aerospace composites market expansion. In addition, the extensive usage of interior and exterior applications will further enhance the overall product penetration. The expansion of commercial and defense industries is expected to witness strong growth during the forecast time frame. Moreover, increasing defense spending will influence the market progression in the coming years.

Over the past few years, there has been a drastic shift toward adopting composite materials over conventional metals. Moreover, the market has been witnessing a drift in the trend of using supersonic and hypersonic missiles and aircraft. With the increasing investment in missile defense spending and orders placed for supersonic military aircraft, the demand for composite material has also significantly increased.

Advancements in manufacturing techniques along with easy machinability will foster composite material demand. Composites can be manufactured in various complex shapes that offer reduced material wastage and corrosion resistance, in turn, further propelling product penetration. The high quality of the composites in outside airframe structures, such as undercarriage, fuel components, and wings, will stimulate the product demand. Strong product penetration in airframe structures will accelerate the industry growth. Aerospace composites market players are focusing on recycling composites for re-usage in the MRO industry, which will spur the product penetration.
Several projects are currently in progress to produce advanced composite materials that offer high strength and are lightweight, which improves the overall performance of aircraft, resulting in the proliferation of the high-speed aircraft and missiles composite material market.

Aircraft manufacturing engineers are testing materials for supersonic flight, which includes both innovative and traditional materials. Several factors such as performance, cost, strength, and weight are taken into consideration for the composite material selection of hypersonic and supersonic aircraft and missiles.

Segments

The global aerospace composites market is segmented by fiber type into carbon fiber composites, ceramic fiber composites, glass fiber composites, others; by aircraft type into commercial aircraft, business and general aviation, civil helicopter, military aircraft, others; by manufacturing process into AFP/ATL, lay-up process, resin transfer molding process, filament winding process, others; by resin type into benzoxazine, cyanate ester, bismaleimide, ceramic and metal matrix, thermosetting resins, polyester, others; by application into interior, exterior.

The commercial aerospace composites market accounted for USD 6 billion in 2020. Growing affordability of flights has increased the number of air passengers traveling in past few years. The growth in the overall passengers will further increase the market revenue. Composites account for more than 50% of the overall market share. Increasing advantages of product usage, such as weight reduction and an increase in the overall efficiency of the aircraft, will fuel the industry size. Moreover, the advantage over other counterparts during manufacturing and molding will support the overall market value.

by Subsystem (Airframe, Propulsion, Avionics, Electrical System, Control System, Weapon System, Undercarriage, Other Systems)

Based on subsystem, the global high-speed aircraft and missiles composite material market is slightly more dominated by the airframe segment. The airframe of a fixed-wing aircraft consists of the five major units that include wings, fuselage, stabilizers, flight control surfaces, and landing gear. Plastic materials and metals such as magnesium, steel, aluminum, titanium, and their alloys are used in the structure of aircraft and missiles. Some of these plastics include reinforced plastic, transparent plastic, composite, and carbon-fiber materials.

Exterior application will gain popularity in the aerospace composites market
The exterior application segment will showcase around 7.5% growth rate through 2027. Exterior aerospace applications require composites, which have higher operating temperatures and better curing properties. They offer sturdy aerospace frames, which will further foster the industry revenue. Continuous R&D in enhancing the performance of commercial and military applications has resulted in increased usage of composite materials owing to their exceptional strength, higher stiffness-to-density ratio, and superior physical properties. Furthermore, aerospace composites reduce production time, have higher damage tolerance during production, and enable 20% weight reduction.

Carbon fiber to dominate the market over the coming years

The carbon segment in the aerospace composites market will dominate 60% of revenue share by 2027. Carbon is widely used to create high-quality precision components used in the manufacturing and treating of high-quality components such as machine plates, nuts, bolts, and posts. Superior strength, hardness, and flexibility are the key factors driving the industry expansion of graphite in aerospace applications. In addition to this, the material is widely used in engine parts, such as impellers and rotors, providing safety against sparks. Lightness, resistance to extreme temperatures, and enhanced strength are the key properties supporting the industry progression. Additionally, graphite possesses self-lubrication properties, providing a stable behavior and reduced maintenance.

Thermosetting resin is majorly preferred in aerospace composites
The thermosetting aerospace composites market is slated to generate a demand of more than 45 kilo tons by 2027. Thermosetting resins are among the most widely used synthetic materials. Easy applicability owing to a change in shape and compatibility with other materials are some of the key properties positively impelling product penetration. These resins are widely used as adhesives and bonding agents. Processing, fabrication, and composite material properties are among the key factors affecting the chemical & physical properties of the resins.

Epoxy is widely used in high-performance materials with a high demand for advanced materials, delivering enhanced performance in aircraft design and assembly along with the repair of interior & exterior aircraft components. Aerospace composites are in high demand as flame, smoke, and toxicity-resistant materials. Growing applications as structural components in aircraft due to their properties, such as enhanced performance in high temperature/high humidity environments, will further support the industry demand. The epoxy material is highly used in interior applications such as insert potting, reinforcement, panel joining, and panel structures

by Material

Fiber Types
Resin Types
Ceramic Matrix Composites (CMC)

Market, By Fiber

Glass
Carbon/Graphite
Ceramic
Aramid
Others

Market, By Resin

Thermosetting
- Epoxy
- Phenolic
- Polyester
- Polyimides
- Others
Thermoplastic
- Polyether ether ketone (PEEK)
- Polysulfone (PSU)
- Polyetherimide (PEI)
- Others

by Manufacturing Process

Automated Fiber Placement
Compression Molding
Additive Manufacturing
Others

North America aerospace composites market will hold over 35% revenue share by 2027. The region dominates the overall aerospace industry with the highest number of commercial and defense aircraft in the world. Increasing exports along with rising demand from the aerospace sector will augment product demand during the forecast timeframe. The U.S. has majorly influenced the market credited to a vast expansion in the aerospace industry along with high demand from the rest of the region will positively impact the overall industry value.

In 2021, the top segment players leading the market include established players providing composite material for the manufacturing of high-speed aircraft and missiles and constitute 60% of the presence in the market. Emerging market participants include start-up entities that account for approximately 15% of the presence in the market. High-speed aircraft and missiles composite material manufacturers and subsystem suppliers account for approximately 25% of the presence in the market.

Some of key Companies include, ACPT Inc., General Dynamics Mission Systems, Hexcel Corporation, Kaman Corporation, Solvay S.A., Teijin Limited, Applied Composites Holdings, LLC, Boston Materials, Inc., Cecence Ltd.,
SGL Carbon SE, Boom Technology, Inc., Brahmos Aerospace Pvt. Ltd., Collins Aerospace, and Lockheed Martin Corporation

Companies induce forward, backward, or full integration strategies between raw material manufacturers, composites manufacturers, and distributors. Aerospace market players mostly adopt forward integrated, involving the manufacturing and distribution of the product.

According to The Business Research Company’s research report on the aerospace composites market, companies in the aerospace market are focusing on technological advancement to accelerate and develop composite material and process technologies for the next generation of energy-efficient aircraft and future mobility. Airlines are trying to replace outdated aircraft with technologically advanced and modern airplanes. These new aircrafts are equipped with increased payload capacities and cost-efficiency. As a result of this, there is widespread adoption of aerospace composites across the globe.

For example, in March 2021, GKN Aerospace, a UK-based company involved in the automotive and aerospace components business, launched a consortium called ASCEND (aerospace and automotive supply chain enabled development). With this launch, the UK has become a technology leader in future lightweight structures. It also helps to reduce carbon emissions and energy consumption in the aerospace industry.

SINTX Technologies, Inc. announced the receipt of a three year Phase II award of $1.5 million issued by the Defense Advanced Research Projects Agency (DARPA)

The award is to develop, design, and characterize thermal-environmental barrier coatings (T-EBCs) for functionally graded high temperature ceramic matrix composites (CMC’s). The proposal was originally submitted by Technology Assessment and Transfer (TA&T), now a wholly owned subsidiary of SINTX. The Phase II award follows the successful completion of the Phase I effort by TA&T.

The goal is to develop gas turbines capable of reliable operation at turbine inlet temperatures up to 3,100°F. This goal is shared across the U.S. armed forces, commercial aviation developers, and also has potential application in industrial gas-turbine power plants. Consequently, there is a driving need to extend the capability of CMCs and T-EBCs to resist degradation in harsh moisture laden combustion and sand/dust ingestion (CMAS) conditions at much higher temperatures than the current state of the art 2,400°F. Technical, economic, and social benefits include improved turbine engine performance, lower fuel consumption and reduced maintenance costs for civilian aircraft, and increased efficiency and reduced pollution for industrial power plants. Energy savings and reduction in climate damaging emissions will provide major societal benefits. Spin off applications include liquid propulsion nozzle extensions, hypersonic components, and nuclear applications among others.

“The continuous temperature increases in efficient, lower emission turbine engines are imposing serious lifetime issues on critical turbine components. This project is designed to develop unique high temperature ceramic composites and environmental protective coatings for the advanced CMCs that will ensure engine performance, increase flight safety, and lower maintenance costs. Spinoffs to commercial aviation and commercial power plants will lower energy costs and reduce environmental pollution,” said Dr. Larry Fehrenbacher, Vice President of Technology, SINTX Technologies. “We believe that this concept has strong merit, and this contract will accelerate SINTX’s path towards scale-up and commercialization.”