International Tribology Council The 9 th International Conference BALTTRIB'2017 Aleksandras Stulginskis University 16–17 November 2017 Lithuanian Scientific Society Department „Tribologija" Akademija, Kaunas, Lithuania Proceedings of BALTTRIB’2017 edited by prof. J. Padgurskas eISSN 2424-5089/eISBN 978-609-449-127-6 https://doi.org/10.15544/balttrib.2017.13 Copyright © 2017 The Authors. Published by Aleksandras Stulginskis University. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC-BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. THE TRIBOLOGICAL PROPERTIES OF PTFE MODIFIED WITH CHALCOPYRITE D. Gventsadze 1* , E. Kutelia ** , L. Nadaraia ** , J. Padgurskas *** , L. Gventsadze ** , O. Tsurtsumia ** * R.Dvali Institute of Machine Mechanics, Tbilisi, Georgia ** Republic Center for Structure Research, Georgian Technical University, Tbilisi, Georgia *** Aleksandras Stulginskis University, Kaunas, Lithuania Abstract: In present work it has been studied the physical-mechanical and tribological properties of the compositional material which was obtained in the PTFE base with chalcopyrite fine dispersed concentrate as fillers. The PTFE-chalcopyrite composites were prepared by powder metallurgy route containing chalcopyrite particles (2.5, 5 and 10 wt %). The tests have been performed in the friction machine under 0.7 MPa load where as a counterpart the gray cast iron was used. From the beginning, the weight wear was measured after passing some velocity steps (0.25–1.25 m/sec). The worn surfaces of the tested composites and the cast iron samples after working as a tribological pair were analyzed using SEM/EDX methods. The obtained results have shown that the incorporation of optimal quantity (~5 wt %) chalcopyrite particles into PTFE matrix drastically (>10 2 times) improves the wear resistance comparatively to the unfilled PTFE in the 0.25–1.25 m/sec friction velocity range. In the same testing conditions by the analysis of the obtained results it is determined that at the low velocity friction (<1 m/sec) the newly developed composite material has 10–15 times lower wear intensity than the best existing tribo–technical purpose commercial material “superfluvis”, therefore the obtained composit e can be considered as a quite inexpensive and efficient tribological material. Key words: self-lubricating composite materials, friction coefficient, polytetrafluorethylene, chalcopyrite, wear intensity. 1. INTRODUCTION For the decades, fillers have been added to politetrafluerene (PTFE) to mitigate the onset of severe wear. The wear reducing mechanism of fillers in PTFE based composites till today remains a topic of debate and technological experiments [1, 2]. Despite the wide and expanding use of solid lubrication in engineering design, there is an increasing demand for the new low friction, low wear materials to improve efficiency and operational life in various environments. It is generally known that the effective functioning of the polymer-based composites as solid self- lubricating materials is directly connected to its ability to form a very thin and uniform highly adhesive wear-resistant transfer film on the surface of the counter body during the wear. Clearly, despite the type of the polymer, the very important role in the formation of friction properties of the transfer film play the nature of the filler particles introduced into the polymer matrix, their composition, shape, dimensions, physicochemical properties, distribution in the volume as well as the degree of compatibility with the matrix [3–4]. Thus, the aims of the proposed work are firstly to study the frictional, wear and transfer responses of the developed new composites based on the PTFE matrix, filled with fine dispersed chalcopyrite particles and 1 Author for contacts: Dr. David Gventsadze. E-mail: david.gven@gmail.com