Shot Peen Forming

MIC’s controlled shot peening process is applied to structures such as aircraft wing skins to create the curvature that enhances lift and efficiency enabling improved fuel economy and reduced environmental pollution.

Through the peen forming process, residual compressive stress acts to elastically stretch the peened side. The surface will bend or “arc” towards the peened side and the resulting curvature will force the lower surface into a compressive state. This precisely engineered and controlled process enables the surface to be manipulated into the desired contours.

Parts formed by peen forming exhibit increased resistance to flexural bending fatigue and where peen formed pieces are processed on one side only, the result causes both sides to have compressive stress. These compressive stresses serve to inhibit stress corrosion cracking and to improve fatigue resistance.

The peen forming procedure can accommodate varying curvature requirements, varying skin thickness, cutouts, reinforcements and pre-existing distortion.

Shot peen forming is a repeatable and cost effective method utilised by many aerospace OEMs to obtain the required skin profiles. Because it is a dieless process, peen forming reduces material allowance from trimming and eliminates costly development and manufacturing time to fabricate hard dies.

The majority of aircraft in production with aerodynamically formed aluminium alloy wing skins employ the peen forming process.