Low Penetration Ball Forming Process

Author:  Brandel, Wynand W. et al
Source:  US Patent 3,705,511
Doc ID:  1972003
Year of Publication:  1972
Abstract:  
A controlled metal deformation process for shaping, forming or contouring metal sheet, plate, and wrought shapes such as extrusions comprising flowing a quantity of metal balls (generally greater in size and mass by several orders of magnitude than standard shot consisting of an aggregate of sizes used in conventional shot peening processes) over the surface to be deformed. The novel process includes impacting the surfaces with metal balls at relatively low velocities, such as by using the force of gravity and resulting in low penetration of ball into metal surface, while the part being formed is in a prestressed condition and moving through the metal ball delivery stream.