TRIBOLOGICAL CHARACTERISTICS OF ANTIFRICTION COMPOSITES OF POLYAMIDE AND ULTRA-HIGH MOLECULAR WEIGHT POLYETHYLENE

Abstract

Analysis of current trends in improving the designs of tribo-couplings of agricultural machinery has shown that the use of polyamide 6 as an antifriction material is limited by its low moisture resistance, which leads to a significant deterioration in its elastic-strength and tribological characteristics during moisture saturation. The paper shows the possibility of using ultra-high molecular weight polyethylene as its analogue, which allows increasing the durability of tribo- couplings of hydraulic systems of agricultural machinery. (Research purpose) The research purpose is in to study the processes of friction and wear of polyamide PA 6 composites and ultra-high molecular weight polyethylene nanocomposites with obtaining dependencies linking tribological characteristics (friction coefficient and wear intensity) with operational factors (temperature, sliding speed and contact pressure). (Materials and methods). Polyamide PA 6 of the 210/310 brand was used in the work; composite of the UPA 6-15A brand, consisting of 85 percent polyamide PA 6 and 15 percent fibrous carbon filler; ultrahigh molecular weight polyethylene of the GUR 4120 brand; Tuballmatrixbeta concentrate of activated carbon nanotubes; hydrophobic nanocrystalline silicon dioxide with a dispersion of 20 nanometers, Nafen grade aluminum oxide nanofiber with a dispersion of 10- 20 nanometers. Samples were made to study the elastic-strength and tribological characteristics of composites by thermal pressing on a Gibitre hydraulic press. Samples were tested on the UAI-7000 M bursting machine and the Haake MARS III rheometer. (Results and discussion) The values of the intensity of linear wear and the dependence of the friction coefficients of composites on the sliding speed, contact pressure and temperature of industrial oil I-20A were determined for the conditions of dry friction and friction with lubrication. (Conclusions) The research results have shown that the use of ultrahigh molecular weight polyethylene and nanocomposites based on it as commercial antifriction materials of tribo- couplings is promising and requires further study.