MICROSTRUCTURE AND TEXTURE DEVELOPMENT IN Ag-Cu ALLOYS SUBJECTED TO SEVERE PLASTIC DEFORMATION

摘要

In this work, modification of microstructure and texture development in Ag and Ag-Cu system alloys (Ag - 4 percent wt. Cu, Ag - 12 percent wt. Cu) subjected to Severe Plastic Deformation (SPD) was analysed. Rods of 15 mm diameter were the starting material for the experiment, they were obtained with the extrusion-torsion (ET) method. Next, the rods were subject to deformation by hydrostatic extrusion (HE) (epsilon = 3.2) and 3 times subjected to Equal Channel Angular Pressing (ECAP) - epsilon = 3.4. As a result of the tests performed, it was found out that the alloys examined, subjected to SPD, displayed a high refinement of the microstructure, which led to a significant improvement of mechanical properties. The microstructure of materials produced by SPD strongly depends on the technological parameters of deformation. In the initial state (ET deformation) all of the alloys exhibited a fibrous character of texture. A similar fibrous texture characteristic was also found after HE, whereas after the ECAP the initial texture was completely changed. In all methods of deformation, the Ag sample shows a very strong texture comparison to Ag - 4 percent wt. Cu and Ag - 12 percent wt. Cu.