Friction, acoustic emission, and wear mechanisms of a PEKK polymer

Abstract

The tribological behavior of a steel/PEKK ball-on-flat contact was studied regarding the load, the velocity and the sliding distance in reciprocating or unidirectional motion. The friction measurements were synchronized with an acoustic emission (AE) device. The results show a behavior change associated with an adiabatic effect on the polymer when the mechanical energy input increases. Two interfacial mechanisms are also characterized: Schallamarch ridges and longitudinal ploughings. These mechanisms are related to two AE frequencies of 0.2 MHz and 1 MHz. The discussion on these two AE populations brings a stronger analysis and completes the friction and the wear mechanisms results.

High Performance Polymer Composites: A Role of Transfer Films in Ensuring Tribological Properties—A Review

“…Yahiaoui, M., et al studied the tribological behavior of the PEEK-steel contact in reciprocating or unidirectional motion by varying load, speed, and sliding distance [ 31 ]. CoF values were reduced due to lowering the load that decreased the contribution of molecular attraction forces, as well as because of the rising speed that cumulated the mechanical energy.…”

Water Jet Erosion Performance of Carbon Fiber and Glass Fiber Reinforced Polymers

“…Figure 8a shows the microscopy of the wear zone corresponding to carbon fiber, in which a slight depth was observed, caused by the number of broken fibers due to the repeated impacts of the liquid on the surface during the test [36]. Figure 8b shows the wear zone of glass fiber where the removal of the polymer matrix and fibers cut randomly by the impact of the liquid on the surface can be seen; in addition, there was the formation of ridges in the direction of impact, which caused an increase in the surface roughness [37,38]. In the sample of carbon fiber with Gelcoat, shown in Figure 8c, the damaged re- Figure 8a shows the microscopy of the wear zone corresponding to carbon fiber, in which a slight depth was observed, caused by the number of broken fibers due to the repeated impacts of the liquid on the surface during the test [36].…”

“…In the sample of carbon fiber with Gelcoat, shown in Figure 8c, the damaged re- Figure 8a shows the microscopy of the wear zone corresponding to carbon fiber, in which a slight depth was observed, caused by the number of broken fibers due to the repeated impacts of the liquid on the surface during the test [36]. Figure 8b shows the wear zone of glass fiber where the removal of the polymer matrix and fibers cut randomly by the impact of the liquid on the surface can be seen; in addition, there was the formation of ridges in the direction of impact, which caused an increase in the surface roughness [37,38]. In the sample of carbon fiber with Gelcoat, shown in Figure 8c, the damaged region was observed, where there was the presence of a small remainder of Gelcoat applied on the surface; additionally, small pitting, formed by the continuous attack, was created, which subsequently caused cracks.…”

Tribolumen: A Tribometer for A Correlation Between AE Signals and Observation of Tribological Process in Real-Time—Application to A Dry Steel/Glass Reciprocating Sliding Contact

“…Before an experimental campaign, a threshold value of 40 dB was chosen to get a finer detection without being disturbed by environmental conditions. Acquisition parameters of AE signals with the peak definition time (PDT), the hit definition time (HDT) and the hit lockout time (HLT) are described in a previous study [5]. Defined values are respectively 200, 800 and 1000 µ s. An amplifier that operates with a single-ended was set at 40 dB.…”

“…Different accommodation mechanisms can occur in a sliding contact between two materials, which can be related to AE sources [2][3][4]. Mechanisms such as asperities adhesion and asperities plowing [5], generation of material debris [6,7] and cracking [8,9] are sources of AE that can generate specific acoustic signatures.…”