Justification of the Composition of a Polymer Composite Material for Structural Purposes for Tribocouplings of Agricultural Machinery

The purpose of the work is to substantiate the optimal composition of polymer-composite materials for use in tribocouplers of agricultural machinery. The study was conducted on the influence of fillers on the physical and mechanical characteristics of a polymer composite material based on polyamide 6. It was found that an increase in the carbon fiber content in the PCM leads to an increase in the yield strength of the resulting composite. At the same time, an increase in the carbon fiber concentration from 15 wt. % to 20 wt. % causes a slight increase in the studied indicator. An increase in the carbon fiber concentration to 30 wt. % allows obtaining a material with a significantly higher yield strength - 86.5 MPa. An increase in the content of BBs in the matrix of the polymer material also leads to an increase in the impact strength. In the case of an increase in the concentration from 15 wt. % to 20 wt. %, the impact strength increases by 8.3%. For the VPA-6-30 material, with a BB content of 30 wt. %, the impact strength increases by 13%, compared to the VPA-6-20 material. It was established that the material VPA-6-15 has the highest relative abrasive wear resistance. Slightly lower values of the indicated studied indicator were recorded in the PCM VPA-6-20 – 0.759. The introduction of silicone lubricant into the PCM contributes to an increase in impact strength, compared to the original material, with a slight decrease in its yield strength. Increasing the concentration of carbon fiber by half from 15 wt. % to 30 wt. % does not significantly affect the yield strength (it increases by only 6.6 %) of the polymer composite material based on polyamide 6, while the impact strength increases by 15 %. It was determined that the highest wear resistance, among the studied materials, is polyamide 6 filled with 15 wt. % carbon fiber. It has been established that the addition of silicone lubricant to a polymer composite material contributes to a significant increase in its impact strength, with a slight decrease in the yield strength, compared to the original material. The effect of this filler on the moisture absorption of the PCM is insignificant.