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The effects of friction on polymeric materials are quite difficult to explain due to the micro and macroscopic interactions of the friction coupling surfaces, which slide over each other. The friction and wear behavior of surfaces in sliding motion can be considered important design criteria. By adding different concentrations of reinforcing agent to the base material, the tribological performance of surfaces in sliding motion can be obtained. The experimental study was carried out on a pin-on-disc type tribological stand under dry friction conditions. The friction and wear behavior was analyzed for two base materials (PTFE and PA66) and the same glass fiber reinforced materials (PTFE + 25% fiber-glass and PA66+GF30). The tests were carried out at different sliding speeds and loading forces, v1=0.20 m/s, v2=0.50 m/s, v3=0.75 m/s and loading forces, Fn1=1.0 N, Fn2=2.5 N, Fn3=5.0 N over a friction length of 5000 mm. Research has shown that the coefficient of friction decreases with increasing loading force. Tests have shown that a high value of the friction coefficient does not mean a high wear rate, the wear rate values are between 10-12 and 10-15 m2/N. TheL(1) presences of the reinforcing agent in the base material have a significant importance on the friction and wear behavior under the action of operating factors (load, sliding speed). [ABSTRACT FROM AUTHOR]

In recent decades, the interest of researchers and engineers in obtaining competitive materials is increasing. The effects of friction on materials are quite difficult to explain due to the micro and macroscopic interactions of the surfaces of the friction couple, which slide over each other. The friction and wear behavior of sliding surfaces can be considered important design criteria. The fact that for a kinematic coupling with sliding motion, a material with a higher hardness is used in most cases in combination with a material with a lower hardness, there is the possibility of abrasion wear and local plastic deformations. The paper proposes in analytical model for calculating the coefficient of friction when a rigid conical penetrator passes over a flat surface with a lower hardness and establishing the response mode of the material of the flat surface. The penetration method corresponds to the deformation produced by asperities in practice. The proposed theoretical model will be experimentally validated on a tribological stand made in this sense. Comparing the experimental results with the theoretical ones confirms the veracity of the model and also corresponds to many of the experimental results obtained in specialized works. [ABSTRACT FROM AUTHOR]

Thermoplastic polymeric materials used in the case of friction couplings with sliding movement such as guides, bearings, linear bearings, must have good tribological properties related to friction and wear. Indication of these characteristics is a convenient means for faster characterization of the tribological behavior of any pair of materials when operating conditions are changed.The paper presents a comparative study of the friction characteristics for two thermoplastic polymeric materials (Relamid B-10-FC and Turcit B Slydway) that slide on a metal surface in dry or oil-lubricated environments.The evolution of the coefficient of friction for a non-compliant and a conforming contact under different operating and lubrication conditions was analyzed. The experimental research was done on a stand of pin on disk tribological tests illustrating graphically the evolution of the coefficient of friction with the load, speed and time for different surface roughness. The values of the normal experimental forces used to act on the pin were: Fn1 = 0.5 N, Fn2 = 1N, Fn3 = 5N, Fn4 = 10N. The rotational speed of the disc can be changed using a variable speed drive. Experimental sliding speeds were: v1 = 0.02 m/s, v2 = 0.0 4m/s, v3 = 0.06m/ s şi v4 = 0.08m/s. The temperature and humidity of the experimental conditions were as well 18°...22° and 60...70%. Each experiment was evaluated for a period of 30 min. The results of this research can be used to design high-performance mechanical systems to improve the various mechanical processes in which friction phenomena occur. [ABSTRACT FROM AUTHOR]