Shear Forming - Flow Forming

Flow Forming is an incremental metal forming technique in which a disk or tube of metal is formed over a mandrel by one or more rollers using tremendous pressure. The roller deforms the workpiece, forcing it against the mandrel, both axially lengthening and radially thinning it. Since the pressure exerted by the roller is highly localized and the material is incrementally formed, often there is a net savings in energy in forming over drawing or ironing processes. However, these savings are often not realized because of the inherent difficulties in predicting the resulting deformation for a given roller path. Flow forming subjects the workpiece to a great deal of friction and deformation. These two factors may heat the workpiece to several hundred degrees if proper cooling fluid is not utilized.

Flow forming is often used to manufacture automobile wheels and can be used to draw a wheel to net width from a machined blank.

During flow forming, the workpiece is cold worked, changing its mechanical properties, so its strength becomes similar to that of forged metal.