Issue 62

Y. S. Rao et alii, Frattura ed Integrità Strutturale, 62 (2022) 240-260; DOI: 10.3221/IGF-ESIS.62.17

Influence of hBN and MoS 2 fillers on toughness and thermal stability of carbon fabric-epoxy composites

Yermal Shriraj Rao, B. Shivamurthy, Nanjangud Subbarao Mohan, Nagaraja Shetty* Department of Mechanical and Industrial Engineering, Manipal Institute of Technology, Manipal Academy of Higher Education, Manipal, Karnataka, India

shrirajrao@gmail.com, http://orcid.org/0000-0003-3653-6977 shiva.b@manipal.edu, http://orcid.org/0000-0002-4273-4884 ns.mohan@manipal.edu, http://orcid.org/0000-0002-1993-3148 nagaraj.shetty@manipal.edu, http://orcid.org/0000-0001-9208-6355

A BSTRACT . Hexagonal boron nitride (hBN) and molybdenum disulfide (MoS 2 ) fillers of 2 to 8 wt.% influence on toughness, microhardness and thermal stability of carbon fabric-reinforced epoxy composite (CFREC) reported. Mode-I, mixed-mode I/II toughness and microhardness of CFREC improved due to the addition of hBN and MoS 2 separately upto 6 wt.% filler loading. The epoxy matrix in CFREC modified by hBN and MoS 2 strengthens the matrix, deflects the crack path and resists delamination. Toughness reduced beyond 6 wt.% filler addition due to agglomeration and poor fiber-filler matrix bonding as revealed by the surface morphology of the fracture specimen. Thermal analysis reveals decomposition temperature at 25% weight loss increased from 395 to 430 °C and 395 to 411 °C due to 4 wt.% MoS 2 and 4 wt.% hBN addition to CFREC respectively. Impermeable characteristics of MoS 2 and hBN fillers caused tortuous diffusion path for gas molecules and delayed thermal decomposition. K EYWORDS . Molybdenum disulfide; Boron nitride; Fracture toughness; Thermal stability; Microhardness; Fracture surface morphology.

Citation: Rao, Y. S., Shivamurthy, B., Mohan, N. S., Shetty, N., Influence of hBN and MoS2 fillers on toughness and thermal stability of carbon fabric-epoxy composites, Frattura ed Integrità Strutturale, 62 (2022) 240-260.

Received: 12.08.2022 Accepted: 27.08.2022 Online first: 28.08.2022 Published: 01.10.2022

Copyright: © 2022 This is an open access article under the terms of the CC-BY 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

I NTRODUCTION

arbon fiber-reinforced epoxy composite (CFREC) is used in aeronautical, railways, automobile, and sports sectors due to its attractive properties [1]. It is used for highly reliable aerospace parts such as wings, tail, and skin panels. Also, used for rocket motors casing and pressure vessels in space applications [2,3]. It is one of the replacements for metals in marine engineering and is used as stiffeners for civil structures and wind turbine blades [4–6]. Due to low shrinkage, chemical inert, heat resistance, easy processability, better impregnation and adhesion properties epoxy is a popular matrix material [7–9]. Its low viscosity at moderate temperature compared to thermoplastics causes uniform spread across the intralayer and interlayer reinforcements [10]. However, its high cross-linking ability develops a three-dimensional C

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