We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

What Is Superplastic Forming?

By Ray Hawk
Updated May 17, 2024
Our promise to you
About Mechanics is dedicated to creating trustworthy, high-quality content that always prioritizes transparency, integrity, and inclusivity above all else. Our ensure that our content creation and review process includes rigorous fact-checking, evidence-based, and continual updates to ensure accuracy and reliability.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

Editorial Standards

At About Mechanics, we are committed to creating content that you can trust. Our editorial process is designed to ensure that every piece of content we publish is accurate, reliable, and informative.

Our team of experienced writers and editors follows a strict set of guidelines to ensure the highest quality content. We conduct thorough research, fact-check all information, and rely on credible sources to back up our claims. Our content is reviewed by subject-matter experts to ensure accuracy and clarity.

We believe in transparency and maintain editorial independence from our advertisers. Our team does not receive direct compensation from advertisers, allowing us to create unbiased content that prioritizes your interests.

Superplastic forming is a specialized metalworking process that allows sheets of metal alloys such as aluminum to be stretched to lengths over ten times that of conventional alloys without degrading the material properties of the metal. The process allows for the manufacture of complex metal parts, which eliminates the need for bolts and fasteners to attach individual metal parts together into a larger unit. Metal forming of this nature is most often used in the aerospace industry, but also has applications for performance sports equipment, as well as in the energy, defense, and medical sectors.

The science of metalworking that is used in superplastic forming is broken down into three deformation conditions: micrograin, transformation, and internal stress superplasticity. The most important method for metals involves micrograin superplasticity, where crystalline grain structures are 10 microns in size or smaller. The temperature of the metal must also be at roughly one-half the melting point of the metal alloy being formed and strain rates range between 0.001 to 0.0001. These conditions limit the types of alloys that will exhibit superplasticity to a small number.

Industrial processes for sheet metal superplastic forming include vacuum and thermoforming, deep drawing, and diffusion bonding. Vacuum forming uses variation in gas pressures to shape metal into a die, while thermoforming uses established processes that are traditional to the manufacture of thermoplastics. Both methods are variations on hot metal gas forming, and have the advantage of requiring only a single die operation to create the part.

Deep drawing is a conventional method used in metal forming that can be adapted to superplastic forming. It requires strain hardening to achieve superplasticity. Thinning and rupture of the metal part, however, are possible in the process, so it is not usually a preferred choice.

Diffusion bonding was not initially a sheet metal forming process, but has been adapted to its use. Aluminum-magnesium alloys are commonly used with the method, and can have an elongation in the superplastic process of up to 600%, but usually don't exceed 300%. Parts created by superplastic forming and diffusion bonding are used in both automotive and aircraft applications that are not structural, and they are not as expensive as high strength alloys.

There are several advantages that metal sheet parts that have undergone superplastic forming have. Since their shapes can be more elaborate and larger due to the increased ability to stretch the metal, they reduce both the weight and cost of aircraft and automotive vehicles as well as metal parts in other industries. Assembly time and complexity is also reduced because fewer parts need to be fastened together. Stresses between multiple metal parts as they age and respond to temperature changes is also minimized.

The industry as a whole contributes to a wide variety of research and new products in the field. The increased versatility of metal sheeting shapes allows for innovation in new streamlining and designs in a multitude of industrial and consumer products. Superplastic forming is also key to innovation in aerodynamic and marine streamlining.

About Mechanics is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Discussion Comments
About Mechanics, in your inbox

Our latest articles, guides, and more, delivered daily.

About Mechanics, in your inbox

Our latest articles, guides, and more, delivered daily.