Hot Forming & Superplastic Forming (SPF)
What is Hot Forming
Hot forming and superplastic forming (SPF) are high-temperature sheet metal forming processes used to shape high-strength alloys that are difficult or impractical to form at room temperature. By introducing heat directly into the forming process, materials such as titanium and other aerospace-grade metals exhibit increased ductility, reduced springback, and improved formability. These processes enable the production of complex, high-precision components while maintaining material integrity and dimensional control. Hot forming and SPF are most commonly used in aerospace, defense, space, and other industries where part performance, weight reduction, and geometric complexity are critical.
When To Use
Hot Forming vs. SPF
While both processes rely on elevated temperatures, they differ in forming mechanics and production characteristics.
Hot Forming
Hot forming uses heated platens with mated tooling to raise the temperature of the blank (900°F+) during the press cycle. Parts are formed while the material is in a softened state, allowing complex shapes to be produced at lower tonnages with reduced springback and cracking. This process is commonly used for low- to medium-volume production and does not significantly alter the material’s microstructure.
Superplastic Forming (SPF)
SPF combines extreme heat (1,650°F+) with controlled gas pressure, typically argon, to form material into complex, near-net-shape components using un-mated tooling. SPF enables very high elongation but involves longer cycle times and is generally reserved for specialized aerospace applications where geometric complexity outweighs throughput requirements.
Custom Hot Forming & SPF Design & Engineering
Hot forming and SPF press design is driven by material behavior at elevated temperatures, part geometry, forming severity, and production objectives. These considerations influence press structure, heating systems, controls, safety features, and overall system configuration.
Material Type & Temperature Requirements
Material selection directly impacts required forming temperatures, dwell times, and tooling design. Titanium alloys are the most common materials formed using hot forming and SPF, though aluminum and other high-strength alloys are also used. Hot forming typically occurs at temperatures ranging from approximately 900°F to 1600°F, while SPF requires higher temperatures, often 1650°F and above, to achieve extreme elongation.
Part Formability Guidelines
Forming force requirements are typically lower than cold forming due to increased material ductility at temperature. However, precise control of forming speed and dwell is critical. Slow forming speeds and controlled dwell times allow stress relaxation and help prevent thinning, tearing, or surface defects. Cycle parameters are highly material and geometry dependent but general guidelines noted below.
- Tonnage: Start at 50 lbs per square in. of part surface area and increase as needed to achieve forming needs.
- Temperature: Start low within required range and increase to achieve the shape and to eliminate springback.
- Speed: Can vary widely, but typical forming speeds are 0.5 – 10 IPM. Approach and retract speeds are programmed at much higher speeds.
- Dwell Times: Dies are held closed for a period of time to stress relieve the parts. Typical minimum time is ~5 minutes.
Safety & Operator Interaction
Hot forming hydraulic presses are designed specifically to manage extreme temperatures safely. Modern systems incorporate insulated forming chambers, automated access doors, guarding, interlocks, and fire-resistant components. These features significantly reduce operator exposure to heat and can minimize required PPE compared to older or retrofitted equipment.
Beckwood Hot Forming & SPF Solutions
Beckwood engineers and manufactures custom hydraulic and servo-electric hot forming and SPF press systems designed specifically for high-temperature forming environments. Each system is engineered around the material, tooling, and production requirements of the application.
Hot Forming & SPF FAQ
What materials are commonly processed using hot forming or SPF?
Hot forming and SPF are most commonly used for titanium alloys, though aluminum and other high-strength aerospace alloys can also be processed depending on application requirements.
What is the difference between hot forming and hot stamping?
Hot forming heats the material within the press using heated platens and does not significantly change the material microstructure. Hot stamping heats material externally and includes a quenching step that alters the microstructure, typically used for high-volume steel applications.
Is hot forming suitable for high-volume production?
Hot forming and SPF are generally best suited for low- to medium-volume production due to longer cycle times associated with heating and dwell requirements.
How complex is it to bring hot forming in-house?
Many manufacturers already have the necessary infrastructure to support hot forming. With purpose-built equipment, the process is often less complex than anticipated and does not require extensive facility modifications.
Can Beckwood design a hot forming or SPF press for my specific application?
Yes. Beckwood specializes in custom-engineered hot forming and SPF press solutions tailored to material type, part geometry, production volume, and facility constraints.