Twist channel angular pressing (TCAP) as a method for increasing the efficiency of SPD

The paper proposes a new variation for the application of SPD methods. Suggested TCAP (twisted channel angular pressing) technology obtains the larger imposed strain more effectively while increasing homogeneity of material. The number of passes needed to obtain the ultra-fine to nano-scale grains in bulk materials can be significantly reduced. Commercially pure copper (99.97%) was used for the experimental verification of the suggested process. The thermal stability of extruded copper was studied after the application of two modes of heat treatment. The deformation parameters of the process were also described using the numerical simulation based on FEM analysis. Predicted value of imposed strain, after a single pass, reached approximately 2.3. Measured strength, determined after four passes, achieved values around 440 MPa homogeneously along the cross-section of the extruded material. The grain size, determined after four passes, averaged out 1.2 μm. Homogeneity of deformation was also confirmed by micro-hardness tests.