Development of Structure at Extrusion of a Strip of Made of Cu through the DRECE Machinery

Achievement of ultra-fine grained （UFG） structure in the strip of sheet is one of the basic problems of the current research in the field of forming. Contrary to bulk forming （processes ECAP, HPT, Conform, etc.）, it is much more difficult to achieve high degree of deformation during 5 to 7-8 passes by the processes ARB, C2S2 （DCAP）. At extrusion of the strip of sheet with use of the process C2S2 the refinement of structure （e.g., in the sheet made of Al） is visible only after 12-15 passes. This is given by the possibility of use of only one type of passes designated in literature as ＂C＂ （pass with turning of material by 180°）. This creates smaller number of different types of shear planes than at the passes of the type ＂Bc＂. The paper gives an analysis of influence of number of passes on structure refinement of a strip of Al sheet on the brand new prototype equipment, DRECE （Dual Rolling Equal Channel Extrusion）. The process was mathematically simulated and results were mutually compared.