Surface and sub-surface degradation of unidirectional carbon fiber reinforced epoxy composites under dry and wet reciprocating sliding

Abstract

In this paper, the effect of water on the friction and wear of a carbon fiber reinforced epoxy tested under reciprocating sliding against a stainless steel counter body is reported. The tribological behavior of unidirectional carbon fiber reinforced epoxy composite was investigated in ambient air and in demineralized water, and the role of water on the (sub-) surface degradation is discussed. The effect of sliding direction relative to the fiber orientation has been studied. The correlation between the debonding of carbon fibers at the fiber-epoxy interface, and the wear behavior of the carbon fiber composite are discussed based on an indepth analysis of the worn surfaces done by environmental scanning electron microscopy, white light interferometry, atomic force microscopy, and focused ion beam. We demonstrate that the carbon fiber reinforcement greatly improves the tribological properties of epoxy under sliding in both dry environment and demineralized water. A reciprocating sliding performed along an anti-parallel direction to the fiber orientation under dry conditions results in a large degradation by debonding and breaking of the carbon fibers compared to sliding in 2 parallel and perpendicular directions. Immersion in water has a harmful effect on the wear resistance of the carbon fiber reinforced epoxy composite. The competition between crack growth and the wear rate of epoxy matrix and/or carbon fibers in the sliding track determines the level of material loss of the composite in both test environments.

Creep and Residual Properties of Filament-Wound Composite Rings under Radial Compression in Harsh Environments

“…De’Nève and Shanahan [ 24 ] concluded that 1% of water uptake in epoxy resin yields 8 C of reduction in . Even in the case of exposure at room temperature, water absorption in the free volume of the epoxy network can increase chain mobility and reduce [ 25 ]. This decrease in can lead to an increase in voids and cracks as well as debonding between fiber and matrix [ 26 ].…”

Identification of fatigue damage modes for carbon fiber/epoxy composites using acoustic emission monitoring under fully reversed loading

“…[8][9][10] Furthermore, anisotropy, heterogeneity, interface properties between the two components of carbon fiber and epoxy matrix result in more complex fatigue behavior. [11,12] The failure of laminate composites during service is mainly due to impact, performance deterioration, and fatigue damage accumulation. Composite laminates showed multiple types of failure during fatigue cycle loadings, such as matrix cracking, interlayer debonding, delamination, and fiber breakage.…”

A study of surface integrity in carbon fiber-reinforced polymer composites cutting with the coupling effect of the multiple machining parameters

“…The surface integrity of a machined component after such machining operations needs to be investigated for assembly purpose, which including surface roughness, subsurface damage and residual stresses. 3,4 Considering the surface integrity has an important effect on the performance of the structural parts, it is of great technological and practical interest to study the surface integrity in machining CFRP composites.…”