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.
Bulk deformation and sheet metal forming.
Rolling forging extrusion and drawing are bulk forming processes.
Bulk forming and sheet metal forming.
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.
Metal forming processes can be classified under two major groups.
Bulk forming processes one is bulk forming and the other is sheet metal forming.
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 defonnation is a metal fonning process where the defonnation is three dimensional in nature.
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.
Most deformation processes and their associated forming machine tools can be placed into one of two groups.
Deformation processes are important in transforming one shape of a solid material into another shape.
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.
Bulk deformation processes and sheet metal working processes.