Nanoscratch testing to assess the fiber adhesion of short‐carbon‐fiber composites

Abstract

In a composite material, the degree of adhesion between the fiber and the matrix plays an important role in the overall performance of the material. Because the load between the fiber and the matrix is realized throughout the interphase region material, a lot of effort has gone into characterizing the strength of the interphase. In this study, nanoscratch tests on the composite samples were used to provide a relative measure of adhesion in different composite materials. Carbon-filled nylon 6,6 and polycarbonate resins were evaluated with this method. The carbon fillers we used were polyacrylonitrile-based carbon fibers sized and surface-treated for the respective matrix and pitch-based carbon fibers without any sizing or surface treatment. Tensile and X-ray photoelectron spectroscopy data for the composites we considered are also presented to compare to the nanoscratch results. It is shown that nanoscratch testing on the composites, with the proposed data analysis, can be an effective tool for determining the relative degree of adhesion between different composites.

Effects of carbon fillers on tensile and flexural properties in polypropylene‐based resins

“…Table IX shows the results for the crest factor, comparing the penetration of the indenter into composites containing 20 wt % in Vectra A950RX LCP and in the polypropylene matrix used in this project 61. Previous research62 has shown that the normalized crest factor (ratio of the composite crest factor to the polymer crest factor) can be used as a measure to compare the relative degree of adhesion between different composites having the same matrix but different types of fillers. A higher normalized crest factor is indicative of a resistance of the composite to scratching, due to better filler/matrix adhesion.…”

Chemical modification of poly(ethylene‐co‐methyl acrylate‐co‐maleic anhydride) for cathodic electrodepositions

“…The critical loads can also be confirmed and collated with observations from a built‐in optical microscope or examined by scanning electronic microscopy and atomic force microscopy. The critical load data is used to quantify the fracture thresholds, and adhesive properties of different coating‐substrate combinations 19, 20…”

Tribological Synergy of Filler Components in Multifunctional Polyimide Coatings

“…This increase of counterbody roughness was also reported due to hard fillers' abrasion [25] or tribochemical oxidation. [28] In the present study, the friction stability is quantified by using the crest factor, which quantifies the amplitude of spikes in friction relative to its root-mean-square value as defined in the work of King et al [29] The lower the crest factor value is, the smoother the sliding process proceeds. Composite coatings C2, C3, and C4 did not withstand test but failed after about 200 cycles of sliding and are not further studied in the following.…”