Most deformation processes and their associated forming machine tools can be placed into one of two groups.
Bulk deformation and sheet metal forming.
The pri mary use of the tenn bulk deformation is to distinguish it from sheet fonning processes.
Bulk deformation is characteristic in that the work formed has a low surface area to volume ratio.
Metal forming processes can be classified under two major groups.
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.
Bulk deformation refers to the use of raw materials for forming which have a low surface area to volume ratio.
Typically metal forming processes can be classified into two broad groups.
Rolling forging extrusion and drawing are bulk forming processes.
Usually the initial shape is a simple one.
Bulk defonnation is a metal fonning process where the defonnation is three dimensional in nature.
Bulk forming and 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.
In sheet metal working the metal being processed will have a high surface area to volume ratio.
Deformation processes are important in transforming one shape of a solid material into another shape.
In sheet forming opera tions the defonnation stresses are usually in the plane of the sheet metal whereas in bulk defonnation the.