Plastic flow in extrusion of metals by experimental investigations and analytical approach

摘要

The analysis of the ability to form composed products under conditions of large plastic deformation in extrusion process has been presented. Experimental research and analytical methods leading to a good description of mechanical behaviour of material in particular in nonaxisymmetric extrusion and multimaterial simultaneous plastic deformation have been carried out. An effect of process variables and characteristics of materials on the deformation pattern and the plastic zones has been discussed. The changeable features of the initial material and the degree of global plastic deformation are taken into consideration to describe the specific character of this type of plastic deformation. It is demonstrated that a proper description of the model of the plastic zone improves the existing theoretical solutions by introducing the results of the actual physical phenomenon. Very good agreement between the results of the experimental investigations of extrusion and co-extrusion of various metals (lead, aluminium, cooper and their alloys) and analytical results has beren found.