Deformation processes are important in transforming one shape of a solid material into another shape.
Bulk deformation and sheet metal forming.
Bulk deformation refers to the use of raw materials for forming which have a low surface area to volume ratio.
Machines for each use tensile compressive and shear stresses or a combination of tensile and compressive stresses to permanently deform the metal into desired shapes.
The key difference between bulk deformation and sheet metal forming is that in bulk deformation the work parts have a low area to volume ratio whereas in sheet metal forming the area to volume ratio is high.
Typically metal forming processes can be classified into two broad groups.
Bulk forming and sheet metal forming.
Bulk forming processes one is bulk forming and the other is sheet metal forming.
Several methods for measuring interfacial friction during plastic deformation have been developed some of which have been listed by wang and lenard 1992 a more comprehensive list applicable to other metal forming processes including bulk and sheet metal forming has been presented by schey 1983 in summary they may be divided into the following categories.
Most deformation processes and their associated forming machine tools can be placed into one of two groups.
Bulk deformation is characteristic in that the work formed has a low surface area to volume ratio.
In sheet forming opera tions the defonnation stresses are usually in the plane of the sheet metal whereas in bulk defonnation the.
Metal forming processes can be classified under two major groups.
In sheet metal working the metal being processed will have a high surface area to volume ratio.
Usually the initial shape is a simple one.
Rolling forging extrusion and drawing are bulk forming processes.