Shot Peen Forming - An Economical Solution

Author:  Tatton, R.J.D.
Source:  Conf Proc: ICSP-3, (p.309-318)
Doc ID:  1987077
Year of Publication:  1987
Abstract:  
Shot peening is a well established cold metal working process used to increase fatigue life and resistance to stress corrosion. Since the late 1940s the process has also gained world wide acceptance, mainly in the aircraft industry, as a method to form components. Most applications relate to A1 alloy wing and fuselage machined skin panels, the first aircraft of which was the Lockheed Constellation. Current production aircraft includes Airbus Industrie A310 an A320, McDonnell Douglas MD80 and Rockwell B1. The panels are formed as a result of the compressive stress induced in the surface. The depth of intensity of this compressive stress can be varied to induce varying radii of curvature and/or to allow for varying thicknesses. As the form is induced by the stresses which result from the shot impact on the surface the process requires no dies. Single double curvature can be induced. An additional bonus from this forming method is that, due to the induced compressive stresses on both surfaces, the component's fatigue life is enhanced, which is the opposite effect of most other forming processes. Descriptors: Aluminum base alloys-- Metal working; Sheet metal-- Metal working; Aircraft components-- Metal working; Shot peening; Bending; Residual stress