Development and research of antifriction nanocomposite for sealing friction units in agricultural machinery

The creation of anti-friction wear-resistant polymer composite materials (PCMs) for the manufacture of individual components and equipment parts is an important task for various branches of agriculture and industry. The use of multi-purpose antifriction self-lubricating PCMs, especially in the friction units of various machines, provides significant reliability and durability of tribotechnical systems while reducing the cost of their manufacture, and also improves the environmental situation when using them. This paper describes the technological process of synthesis of composite nanomaterials based on polytetrafluoroethylene (PTFE) with nanoscale fillers-modifiers of various chemical nature: 1) the product of processing of hydrocarbon raw materials - carbon black (CB) grade N 220; 2) Aerosil R 106 (silicon dioxide). The production of antifriction nanocomposites was carried out according to the standard technology of cold pressing of components followed by heat treatment of pressed blanks. A significant concentration effect of both individual nanocomponents and complex composition on the tribotechnical characteristics of the developed polymer composite materials was noted. The minimum wear rate of the PCM during frictional interaction with a metal counterbody without the use of lubricant was noted when using complex fillers. As a result of the conducted research, the optimal composition of nanoscale fillers-modifiers of various chemical nature for PCM based on PTFE was established: CB N 220 - 2.0 mas.%, Aerosil R 106 - 0.6 mas.% (sample No. 3). The coefficient of friction of the sample is 0.065; the wear rate is 2.3 ∙ 10-4 g/h, which is lower than the wear rate of the PCM with the monomodifier Aerosil R 106 by 17.9%, with the monomodifier CB N 220 - by 34.3%. The developed antifriction nanocomposite can be recommended as a seal for friction units in wheeled and tracked vehicles of the agro-industrial complex.