Shot Peen Forming
Shot Peen Forming uses the compressive stress induced by controlled shot peening to create a change in the component shape. Gentle curves within the elastic range of the material are regularly formed to consistent tolerances.
Varying curvature requirements, material thickness, cutouts, reinforcements, and pre-existing distortion can all be processed with Shot Peen Forming. Following peen-forming both sides of a wing skin have compressive stress which offers enhanced fatigue protection on the whole component.
Curtiss-Wright Surface Technologies’ shot peen forming is a dieless process performed at room temperature. Every piece of shot acts as a tiny peening hammer producing elastic stretching of the upper surface and local plastic deformation that manifests itself as a residual compressive stress. The combination of elastic stretching and compressive stress causes the material to develop a convex curvature on the peened side.
Shot Peen Forming Benefits
• Resistance to Flexural Bending Fatigue and Stress Corrosion Cracking
• Performed With or Without an External Load Applied on the Component
• Thicker Cross Sections Requiring Forming
Laser peening is an alternative technique for thick component section peen forming. With much deeper compressive stress over conventional shot peeing, thicker cross-sections can be formed or a tighter radius of curvature can be achieved.
• No Forming Dies Required
Although no dies are required for shot peen forming, for severe forming applications, stress peen fixtures are sometimes used. This process is effective on all metals, even honeycomb skins and ISO grid panels and is often more effective in developing curvatures than rolling, stretching or twisting of metal. Saddle-back shapes also are achievable. The shot peen forming process also is flexible to design changes, which may occur after the initial design.
• Performed At Room Temperature
• Correction of Distortion
Shot Peen Forming Applications
- Airframe components
- Rocket structure