One of the most important material removal methods is a collection of material work-in-processes in which power-driven machine tools, such as lathes, milling machines, and drill presses are used with a sharp cutting tool to mechanically cut the material to achieve the desired geometry.
Shot peening is a cold work-in-process in which small spherical media called shot bombard the surface of a part. Nearly all fatigue and stress corrosion failures originate at the surface of a part, but cracks will not initiate or propagate in a compressively stressed zone. The overlapping dimples from shot peening create a uniform layer of compressive stress at metal surfaces, providing considerable increases in part life.
The shot peen forming process is ideal for forming large panel shapes where the bend radii are reasonably large and without abrupt changes in contour. Shot peen forming is best suited for forming curvatures where radii are within the metal's elastic range.
