In-situ study of structural evolution of tribological materials using synchrotron radiation

In this paper, we propose an approach for estimation of structural changes at the surface of metallic materials during running-in stage of friction. The application of synchrotron microbeam for in-situ observation of structural evolution in thin layers subjected to friction load is substantiated. A design of experimental apparatus intended for in-situ studies of friction processes using synchrotron radiation is described. This apparatus maintains constant position of the sample surface with respect to the incident beam. The ring shaped experimental sample with a thickness of 1 mm is pressed with constant pressure against a pin shaped indenter and rotated with constant speed. The pressure on the sample is determined by the mass of the load placed in the loading basket. The surface of the sample that comes out of indenter is probed by synchrotron beam. The proposed experimental scheme allows receiving X-ray diffraction patterns even under condition of severe plastic deformation of the surface. The preliminary results on the synchrotron assisted study of the dry friction of a Cu sample are described.