The aerospace industry relies on adhesives for numerous structural applications within an aircraft or its parts, such as filling gaps, bonding components, sealing, stabilizing, or completing repairs. Companies can modify both the viscosity and thickness of these highly versatile adhesives to tailor them to a specific application. Incorporating additives into an adhesive can further enrich its properties and help customize its strength or curing time. Read on to learn more about the beneficial qualities of aerospace structural adhesives and the different types available.
Benefits of Structural Adhesives in Aerospace Applications
Adhesives play a significant role in the aerospace industry, offering many advantages to its applications. These include:
Strength. Depending on the type, structural adhesives can offer impressive shear, tensile, peel, and compressive strengths. Some adhesives are even capable of forming a more robust and durable joint than rivets and welding.
Versatility. Structural adhesives help join similar and dissimilar aircraft parts, with bonds capable of carrying greater weight loads due to their even stress distribution. These adhesives are also ideal when joining dissimilar material substrates like stainless steel, aluminum, titanium, or composites.
Ease of use. With adhesives, no holes, fastenings, or rivets are necessary. This makes them easy for users to apply while also ensuring that the adhesives will not compromise the integrity and strength of an aircraft's components.
Savings. Joining parts using adhesive is easy and quick, and it helps to cut labor and material costs. Their ability to cure rapidly and at room temperature also cuts down on energy use and generates time savings.
Aesthetics. Adhesives do not destroy a plane's aesthetics and structural beauty, as their application does not involve any invasive mechanical work such as drilling or utilizing nuts and bolts. This allows for greater design possibilities, as well.
Fatigue resistance. In the life of an aircraft part, fatigue can occur to metals, plastics, and adhesives due to wear, impact, and dynamic movement. This can potentially weaken the strength of these materials, leading to premature failure. To curb this, many adhesives have high impact and shear strengths that resist cyclic fatigue.
High transition temperatures. Glass transition temperature is the point at which an epoxy changes its form, transitioning from hard, glass-like material to a ductile, rubbery compound. Possessing high glass transition temperatures, structural adhesives work well in high-heat applications.
Types of Structural Adhesives for Aerospace Applications
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Aerospace applications make use of several types of structural adhesives, which mainly differ in their chemical composition, load-carrying capacity, form, and reactivity or inertness. Some of the common types of structural adhesives include:
These adhesives cure quickly at room temperature and are applicable for a variety of substrates, such as glass or metal, for material flexibility. They are advantageous for their high shear, tensile, and peel strengths, as well as their impact resistance. Structural adhesives are applicable in numerous aerospace tasks, including adhering harness clips or bonding magnets within electric motors.
These one- or two-part adhesives also cure quickly, with options for room-temperature, thermal, or UV curing. Epoxies typically have high shear and peel strengths even after exposure to extreme thermal or environmental conditions, chemicals, or impact. This makes them a durable option for bonding dissimilar materials and gap filling. Also, as weight is a critical consideration in aerospace applications, epoxies are ideal for their light weight and low density.
Another adhesive type that cures at room temperature, cyanoacrylates cure within seconds to a variety of substrates after exposure to moisture in the air. Their superior shear and tensile strengths make them a good option in applications that require permanent bonding, quick repairs to items such as interior trim, or working in conjunction with another adhesive that is slow to cure. Cyanoacrylates also go by the names CA adhesives, superglues, or instant adhesives, among others.
High-Performance Adhesives From Robert McKeown Company
Since 1937, Robert McKeown Company, Inc. has developed a reputation as a reliable resource for high-quality structural adhesives in the aerospace industry and more. Our experience fabricating electronic and engineered materials allows us to provide customized bonding or sealing solutions in-house regardless of your application. Contact us for more information on our products or request a quote today to begin your project.