The micro/macro mechanical approach of reinforced braid composite used in tribology

Abstract

Self-lubricant composite is a flourish scope of technology that merits academic and industry attention, as it is a specific part which essentially employed in acute operation conditions. In the present study, the mechanical properties of the self-lubricating composite of two-dimensional (2D) and three-dimensional (3D) braid were investigated. The composites contained Polytetrafluoroethylene (PTFE) fibers as a lubricant and glass, carbon, and Kevlar as a reinforcement, hierarchically incorporated into the structure. In order to study the composite behavior as well as to determine the modulus and hardness of the sample, an indentation test, which is very similar in loading to abrasion tests, was applied. A microband test was also conducted to assess the adhesion between the resin and the PTFE fiber. Shear punch tests were performed to evaluate the total shear strength and impact test to estimate energy absorption and impact strength. The results showed that PTFE/epoxy matrix has poor adhesion. Composites with higher PTFE volume fraction had good energy absorption and, at the same time, low shear strength. The higher modulus of carbon composites was concerned.

Influence of Nitrile Butadiene Rubber (NBR) Shore Hardness and Polytetrafluoroethylene (PTFE) Elastic Modulus on the Sealing Characteristics of Step Rod Seals

“…For the PTFE material, it exhibits excellent linear and isotropic material properties, with consistent mechanical strength, thermal stability, and electrical insulation ability. According to the work of Zahabi et al [21] and Bao et al [22], the elastic modulus of PTFE material is statistically considered to be an increasing function of hardness, and it can be obtained by indentation technique or the Oliver-Pharr method.…”

On the tribology of complex 2D/3D composites bearing

“…Although, the poor interfacial shear strength (IFSS) value of PTFE has suppressed their potential for use in various applications. 4,12 Despite enormous studies performed on multiple methods for embedding solid lubricant in composites, too little attention has been paid to use hierarchical braid structure. Wang and Yan, 13 Bahadur et al, 14 and Yang 15 indicated that PTFE composite wear life is brief because it cannot shape durable tribofilms.…”

“…The absorption of stresses generated during wear at the friction composite interface is mainly done by fibers. [3][4][5] Thanks to its intrinsic self-lubrication, high modulus/strength, and good thermal stability, carbon fiber can be used in various composites. 6 However, some works have yielded contradictory findings concerning the influence of carbon fiber on tribological behavior, indicating poor frictional properties.…”

Evaluating the tribological and mechanical properties of filament wound composite incorporated with PTFE fibers and tungsten carbide filler applicable for self-lubricating bearings

“…In addition to the tribological properties, mechanical characteristics of the composite must be analyzed [25]. One of the tests to examine the strength of bearings is the compressive strength test because the bearings are affected by radial loads [26].…”