OBRABOTKAMETALLOV MATERIAL SCIENCE Vol. 27 No. 1 2025 speed, which corresponds to a three-stage wear pattern: an initial increase, reaching a maximum value, and a steady-state wear stage for each sliding speed. The minimum wear is observed at a speed of 2.0423 m/s, and the maximum at 6.1269 m/s, which emphasizes the significant influence of sliding speed on the wear process. Influence of bentonite clay concentration on the wear resistance of the composite The wear curve (Fig. 4) demonstrates the influence of the bentonite clay content on the wear of the composite. Composites without clay are characterized by the highest wear. Increasing the clay content to 3 % leads to a reduction in wear. Further increasing the clay content (to 5 and 7 %) causes an increase in wear, which indicates the existence of an optimal clay concentration. Fig. 4 shows a decrease in wear for composites with 1 and 3 % bentonite clay and an increase in wear for composites with 5 and 7 % clay. The composite with 7 % clay demonstrates the highest wear. Therefore, to minimize dust formation when used in brake and clutch plates, the clay content should not exceed 3 %. An increase in wear with increasing load is also noted. The obtained results are supported by microscopy and energy-dispersive spectroscopy (EDS) data, presented in Figs. 5 and 6. At the initial stage of the tests, an increase in the wear rate is observed, which corresponds to the theory of adhesive wear and is due to the interlocking of asperities on the surface of the disk and the composite pin. As the tests continue, material transfer to the disk occurs, which temporarily increases the wear rate. At the final stage, the wear rate stabilizes. In the case of samples with bentonite clay, a decrease in wear is observed at the initial stages, which is associated with adhesion and the abrasive effect of agglomerated clay. Composites with 1 and 3 % clay show less wear, while composites with a clay content of 5 % or more demonstrate increased wear due to clay agglomeration (Table 5). Influence of transfer film formation on wear The formation of a transfer film on the counterface plays a crucial role in determining the tribological behavior of polymer composites. After the formation of a transfer film, the interaction occurs between the polymer and the material of the film, rather than with the polymer counterface. Studying the characteristics of transfer films is necessary for understanding wear mechanisms. The morphology of the worn surfaces of composites with varying clay content, investigated by scanning electron microscopy (SEM), is presented in Fig. 5. Fig. 3. Effect of Sliding velocity on Wear at constant Load of 20 N
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