Ivo Szurman

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.

The Methods of Preparation of Ti-Ni-X Alloys and Their Forming

The continuous development of science and technology in all industrial sectors means connecting and usage of a wide range of new knowledge together with implementation of new modern technologies for production of materials with high functional, specific and special properties. Intermetallic compounds TiNi with shape-memory effect are an interesting group of materials. These materials are used in a wide range of industry, such as electronics, robotics, tele-communication and also in medicine and optics. Shape-memory alloys (SMA) are a group of materials characterized by shape-memory effect (SME) and superelasticity (SE), also called pseudoelasticity.