Preprint Article Version 1 Preserved in Portico This version is not peer-reviewed

Operando in-SEM Study of Micro-Deformation and Fracture Behaviour of Carbonized Elastomer-Based Composites

Version 1 : Received: 11 December 2020 / Approved: 11 December 2020 / Online: 11 December 2020 (11:31:29 CET)

A peer-reviewed article of this Preprint also exists.

Statnik, E.S.; Ignatyev, S.D.; Stepashkin, A.A.; Salimon, A.I.; Chukov, D.; Kaloshkin, S.D.; Korsunsky, A.M. The Analysis of Micro-Scale Deformation and Fracture of Carbonized Elastomer-Based Composites by In Situ SEM. Molecules 2021, 26, 587. Statnik, E.S.; Ignatyev, S.D.; Stepashkin, A.A.; Salimon, A.I.; Chukov, D.; Kaloshkin, S.D.; Korsunsky, A.M. The Analysis of Micro-Scale Deformation and Fracture of Carbonized Elastomer-Based Composites by In Situ SEM. Molecules 2021, 26, 587.

Journal reference: Molecules 2021, 26, 587
DOI: 10.3390/molecules26030587

Abstract

The carbonized elastomer-based composites (CECs) possess a number of attractive features in terms of thermomechanical and electromechanical performance, durability in aggressive media and facile net-shape formability, but their relatively low ductility and strength limit their suitability for structural engineering applications. Prospective applications such as structural elements of MEMS can be envisaged, since smaller principal dimensions reduce the susceptibility of components to residual stress accumulation during carbonization, and to brittle fracture in general. We report the results of operando in-SEM study of micro-deformation and fracture behavior of CECs based on NBR elastomeric matrices filled with carbon and silicon carbide. Nanostructured carbon composite materials were manufactured via compounding of elastomeric substance with carbon and SiC fillers using mixing rolling mill, vulcanization, and low-temperature carbonization. Double Edge Notched Tensile (DENT) specimens of vulcanized and carbonized elastomeric composites were subjected to in situ tensile testing in the chamber of the scanning electron microscope (SEM) Tescan Vega 3 using Deben Microtest 1 kN Tensile Stage. The series of acquired SEM images were analyzed by means of Digital Image Correlation (DIC) using Ncorr open source software to map the spatial distribution of strain. These maps were correlated with Finite Element Modelling (FEM) simulations to refine the values of elastic moduli. Besides, the elastic moduli were derived from unloading curve nanoindentation hardness measurements carried out using NanoScan-4D tester and interpreted using the Oliver-Pharr method. Carbonization causes significant increase of elastic moduli from 0.86 ± 0.07 to 14.12 ± 1.20 GPa for the composite with graphite and carbon black fillers. Nanoindentation measurements yield somewhat lower values, namely, 0.25 ± 0.02 GPa and 9.83 ± 1.10 GPa before and after carbonization respectively. The analysis of fractography images suggests that crack initiation, growth and propagation may occur both at the notch stress concentrator and relatively far from the notch. Possible causes of such response are discussed, namely, (1) residual stresses introduced by processing; (2) shape and size of fillers; and (3) the emanation and accumulation of gases in composites during carbonization.

Subject Areas

composite materials; carbonized elastomeric matrices; C/SiC fillers; μ-DENT; in situ tensile test; Deben Microtest; Tescan Vega 3; NanoScan-4D; Digital Image Correlation (DIC).

Comments (0)

We encourage comments and feedback from a broad range of readers. See criteria for comments and our diversity statement.

Leave a public comment
Send a private comment to the author(s)
Views 0
Downloads 0
Comments 0
Metrics 0


×
Alerts
Notify me about updates to this article or when a peer-reviewed version is published.
We use cookies on our website to ensure you get the best experience.
Read more about our cookies here.