Epoxy Matrix Composites Research Articles

Effect of Drilling Parameters and Tool Diameter on Delamination and Thrust Force in the Drilling of High-Performance Glass/Epoxy Composites for Aerospace Structures with a New Design Drill

Real service requirements of the assembly performance and joining properties of design components are critical for composite usage in the aerospace industry. This experimental study offers a novel and comprehensive analysis of dry drilling optimization for glass-reinforced, high-performance epoxy matrix composites used in aerospace structures, focusing on thrust force and delamination. The study presents a first-time investigation into the combined effects of spindle speed (1000, 2250, 4000 and 5750 rpm), feed rate (0.2, 0.4, 0.6 and 0.8 mm/rev) and tool diameter (3 and 5 mm) using a custom-designed drill tool specifically developed for this application, filling a gap in the current literature. By employing the Taguchi design of experiments, the study identified that medium spindle speeds (2250–4000 rpm), lower feed rates (0.2 mm/rev) and smaller tool diameters (3 mm) provided optimal conditions for minimizing thrust force and delamination. These results present actionable insights into improving the structural integrity and performance of drilled aerospace-grade composite components, offering innovative advancements in both the aerospace and defense industries.

Effect of wheat bran filler particulates nettle fiber reinforced epoxy matrix composite − A novel material for thermal insulation application

This research examines the mechanical and thermal characteristics of composites made from nettle fiber-reinforced wheat bran filler particulate epoxy framework. It highlights the influence of different filler materials on the performance of these composites. A thorough examination of mechanical properties was carried out, focusing on the flexibility, bending strength, impact resistance, and Shore D hardness. The malleable quality was completely changed by adding a filler ingredient, reaching a peak of 51.36 MPa. The flexural strength reached 47.38 MPa, showing excellent ability to withstand loads. The assessment of affect quality reached a maximum of 13 kJ/m2, indicating high energy absorption and durability. The Shore D hardness, which indicates the surface’s ability to resist indentation, ranged from 52 to 61, indicating differences in the stiffness of the composite material. The addition of bran filler to this composite provides an ideal thermal conductivity value of 0.98 W/mK. The morphological properties of the composites were analysed using Scanning Electron Microscopy (SEM), which provided detailed insights into their internal structure. The SEM images revealed a uniform distribution of nettle filaments and bran fillers inside the epoxy matrix, with well-formed samples exhibiting strong fiber–matrix adhesion and minimal voids.

Research progress on high-temperature properties of carbon fiber reinforced polymer composites for cables

Carbon fiber reinforced polymer composites (CFRP) cable has advantages of lightweight, high strength, and excellent durability, providing a new materials for cables and bringing out potential breakthrough in spanning capacity of structures. At present, CFRP cable has already been applied in some engineering bridges. The fire resistance performance of CFRP cable is critical for ensuring structure safety when suffering accidental fire disaster, and clarifying mechanical performance deterioration and failure mechanism of CFRP cable at elevated temperature is fundamental for research of its fire resistance. This paper summarizes current research progress on high-temperature properties of CFRP cable from two levels, including epoxy resin matrix and CFRP composites. Firstly, at resin matrix level, mechanical properties of epoxy resin and its degradation at elevated temperatures are reviewed and analysed, and potential ways to improve high-temperature performance of epoxy resin are suggested. Secondly, at CFRP composites level, high-temperature properties test methods and mechanical performance of CFRP composites in longitudinal direction and transverse direction at elevated temperatures are summarized and discussed. In addition, research shortage of high-temperature properties of CFRP cable is summarized, and corresponding further research is recommended.

Boron nitride nanosheets synergized with two‐dimensional micron silver sheets to enhance thermal conductivity and insulation of epoxy resin composites

AbstractWith the rapid progress of the advanced electronic device industry, precision electronic instruments are gradually developing towards miniaturization. In this case, epoxy resin gradually attracts people's attention, but its intrinsic thermal conductivity is not high, and the resulting heat dissipation problem limits the further application of epoxy resin in the field of electronic packaging. Therefore, how to enhance the thermal conductivity of epoxy resins has become an urgent problem in the field of electronic packaging. In this work, BNNS was successfully prepared by stripping h‐BN into a flaky two‐dimensional material, which was added to the epoxy resin as a filler to make the composite material. And on the basis of the above, two‐dimensional micron silver flakes (AgMS) with different mass fractions were added to the composites, and the AgMS/BNNS/EP composites were successfully prepared. When BNNS was 25 wt% and AgMS was 1 wt%, its out‐of‐plane thermal conductivity was enhanced from 0.17 W m−1 K−1 of pure epoxy resin to 0.43 W m−1 K−1. When BNNS was 20 wt% and AgMS was 1 wt%, the breakdown strength was enhanced from 105 kV/mm for pure epoxy to 130 kV/mm. This work provides a new strategy for synthesizing high‐thermal‐conductivity epoxy matrix composites.

Facile armour production from cocoon waste by a cold-pressing process

Utilising cocoon waste as reinforcement in composites offers a cost-effective alternative for soft body armour production. Cocoon waste, including damaged or uncoiled cocoons and those with pupae, is recognised as an eco-friendly choice. This study aims to develop and assess the incorporation of varying amounts of cocoon waste as reinforcement in epoxy resin matrix composites through the cold-pressing process. The cocoon waste content in the composite specimens ranged from 0 to 40 wt%. Tensile testing and ballistic impact testing were conducted to evaluate specimen performance. The cocoon waste composite plate exhibited a maximum tensile strength of 62.21 MPa at 30 wt%, slightly surpassing that of woven hemp. These findings indicate the advantageous reinforcement attributes of cocoon waste. However, a limitation was identified: bullets fully penetrated the composite plate. To address this, ultra-high-molecular-weight polyethylene was incorporated into cocoon waste composites, resulting in enhanced tensile strength (107.36 MPa) and complete bullet penetration prevention. These outcomes position the study as a promising avenue for developing body armour plates meeting the stringent level II certification standards set by the National Institute of Justice.

Fabrication and Characterization of Jute Fibre Reinforced Polymer-based Decorative Composites: Effect of Gamma Radiation

The jute fibre (JF) reinforced polyethylene (PE), polypropylene (PP), and epoxy resin (ER) matrix composites were developed. The JF content was maintained to 30% by weight. Then tensile properties and impact strength were measured. The finest tensile properties were found for JF/PP composites. The tensile strength (TS), tensile modulus (TM), elongation at break (Eb%), and impact strength (IS) of the JF/PP composites were found to be 38.00 MPa, 1800 MPa, 12%, and 8.20 kJ/m2 respectively. The bonds between JF and polymers of the developed composites were investigated and found good adhesion. The composite samples were exposed to gamma ray and it was found that gamma radiation have the potential to improve the tensile and impact strength of the JF-based polymer composites. The JF content polymer-based decorative composites were also developed. The outcomes of this investigation showed a minor decrease of the tensile and impact strength of the composites but enhanced the beauty of the composites noticeably. The developed JF/polymer composites have sufficient mechanical strength for many applications pretty. J. of Sci. and Tech. Res. 5(1): 75-82, 2023

A Novel Route to Glass Fiber‐Reinforced Epoxy Matrix Composites: Visible Light Activated Radical Induced Cationic Frontal Polymerization

AbstractIn the current study, a novel radical‐induced cationic frontal polymerization (RICFP) concept capable of rapid curing at room temperature via visible light irradiation is represented. Initially, the optimal formulation, which can be most effectively cured with visible light irradiation, is determined based on thickness, hardness, curing speed, and mechanical properties using FT‐IR, DSC, TGA, and flexural test methods. Subsequently, the viability of the method is illustrated by fabricating glass fiber‐reinforced composites through the hand lay‐up technique, employing the optimized formulation and glass fibers in various forms (chopped strand mat and biaxial). Mechanical properties of the obtained composites, including bending, tensile, and shear tests, are carried out according to relevant international standards and compared with reference composites thermally cured with amine‐based hardener by conventional method.

Study on the mechanical and thermal properties of aramid fibre reinforced with sawdust particulates in an epoxy matrix composite: a novel material for structural applications

AbstractThis study investigates the development and characterization of a novel composite material for structural applications, aiming to address the growing demand for lightweight, durable and versatile materials. The composite integrates aramid fibre reinforced with sawdust particulates within an epoxy matrix. Methodologically, the composite was fabricated using a hand layup process, ensuring even distribution and strong adhesion between components. Mechanical testing revealed significant enhancements in tensile strength (up to 135.29 MPa) and flexural strength (up to 136.92 MPa) with the inclusion of sawdust particulates, optimizing stress distribution and impact resistance. Hardness was also improved, peaking at a Rockwell hardness number of 94. Thermal analysis demonstrated moderate thermal conductivity (1.92 W mK−1) and a high heat deflection temperature (109 °C), indicating excellent thermal stability. SEM provided insights into the composite's microstructure, confirming uniform sawdust distribution and robust fibre–matrix adhesion. These findings underscore the potential of this composite for lightweight, durable and thermally stable structural applications. © 2024 Society of Chemical Industry.

Mechanical performance of epoxy matrix composites reinforced by physically and chemically treated hemp fiber

Mechanical performance of epoxy matrix composites reinforced by physically and chemically treated hemp fiber

Mo2Ti2C3 and PTFE synergistically functionalized corrosion-resistant, thermally conductive, super abrasion-resistant epoxy resin composite coating

Epoxy resin (EP) matrix composites are a widely used polymer-based protective coating material. However, the low lubricity leads to frictional wear problems that make their large-scale development and application a serious challenge. Based on this, a multifunctional composite coating (MPT-EP) with low wear, high lubricity, high thermal conductivity, and corrosion resistance was prepared by introducing polytetrafluoroethylene (PTFE) and lamellar Mo2Ti2C3 as a composite lubricant into epoxy resin matrix using a simple solvent dispersion method. The results showed that the introduction of the composite lubricant resulted in enhanced hardness and mechanical properties of the composite coating. Compared with the single epoxy resin coating (0.31), the friction coefficient (COF) of the composite coating was only 0.22, and the friction surface did not show obvious abrasion marks. The surface temperature of the composite coating was up to 51.4 °C when it was placed on a hot bench at 60 °C for 60 s. In addition, the COF of the composite coating did not change significantly after being immersed in acid, alkali and salt solutions. Therefore, the Mo2Ti2C3-induced multifunctional epoxy resin matrix composites have important application potential and research value in the field of ultra-wear-resistant and high lubrication protective coatings.

Response of short jute fibre preform based epoxy composites subjected to low-velocity impact loadings

This work aimed to investigate the low velocity impact behaviour of short jute fibre non-woven preform epoxy matrix composites experimentally. Dry fibre preforms were developed using an optimised process and a laboratory made preforming device. The effects of alkali and poly vinyl alcohol (PVA binder) treatments on impact performances of jute composites were investigated and compared at 3 J and 6 J impact energy levels. To identify the failure modes of tested composites, the X-ray µCT tomography was employed. The results demonstrated that the developed untreated short jute fibre preform reinforced composites absorbed a higher impact energy, when they were compared to treated (alkali or PVA binder) composites. For untreated composites, maximum impact forces at 3 J and 6 J energies, were found as ⁓2478 N and ⁓2319 N, respectively; for the PVA treatment these values were measured as ⁓2457 N and ⁓2216 N, while, at same energy levels, alkali treated composites showed the lowest values as ⁓1683 N and ⁓1440 N, respectively. Untreated jute fibre contains natural matrices such as hemicellulose, lignin and waxes, which ensured a positive response to absorb more energy upon impact loading. In contrast, the alkali treatment facilitates a highly fibre packed composite structure, which accelerated the impact crack propagation in tested composites, resulting in lower resistance to impact energy. Although, PVA treated composites showed reduced impact properties compared to untreated composites due to the PVA polymer brittleness on the treated fibre surface during the impact incidents, this treatment demonstrated better impact responses over the alkali treatment. The application of PVA binder on alkali-treated fibres provided an extra support to fibres and a better fibre/matrix interface and hence, this combined treatment demonstrated a slightly better impact resistance (⁓2027 N and ⁓1874 N impact forces at 3 J and 6 J respectively) compared to only alkali treated fibre composites. The SEM fracture images and the X-ray µCT damage analysis revealed different impact damage modes, which supported the observed impact results. The obtained results from this investigation could be helpful for using short jute fibre composites in various load demanding applications where impact incidents are likely to be happened.

Tannic acid/polyethyleneimine functionalized hexagonal boron nitride: Enhancing tribological properties of epoxy-based composite coatings

The interfacial compatibility issue of boron nitride (BN) nanofillers in epoxy resin (EP) matrix is one of the major challenges plaguing the efficient application of composites. Herein, inspired by phenol-amine green chemistry, microwave-assisted ball milling was used to synthesize tannic acid (TA) and polyethyleneimine (PEI) functionalized boron nitride (TA/PEI@BN). Characterization indicated that TA/PEI grafted on BN via both non-covalent and covalent interactions, which improved the interfacial compatibility and cross-linking properties of TA/PEI@BN within the EP. Meanwhile, the introduction of 0.25 % TA/PEI@BN reduced the average friction coefficient and wear rate of the EP composite coating by 17 % and 50 %, respectively. The characterization of the friction interface showed that TA/PEI@BN could exhibit a "sliding complementary repair" effect during friction. This work presents a novel, green, and scalable method for realizing the surface functionalization of BN, beneficial for the further application of high-performance epoxy matrix composites.

Impact of different matrix systems on mechanical, thermal, and electrical properties of carbon fiber reinforced epoxy resin matrix composites

AbstractCarbon fiber reinforced epoxy resin matrix composite is one of the most important composite materials in the world. Many researchers have conducted a lot of research on epoxy resin matrix systems in recent years, mainly to improve the problem with the short curing time of the matrix system and epoxy resin's high viscosity. The final aim is to enhance various aspects of composites' performance and optimize the production process. A new type of water dispersed epoxy resin matrix system is investigated in this paper and the target is to optimize the mechanical, thermal, and electrical performances of the composites with the water dispersed epoxy resin matrix by varying different doping particles and different resin/catalyst ratios. Through a series of experiments, it is evident that varying the ratio of resin to catalyst in the matrix system will not significantly improve the mechanical as well as thermal properties of the composites. However, increasing the amount of catalyst in the matrix system can greatly improve the electrical properties of its composite samples. In addition to this, the addition of doping particles to the matrix systems has the effect of slightly enhancing the tensile modulus, thermal conductivity, and electrical conductivity of their composites.Highlights A new water‐dispersed epoxy resin matrix system improves processing technology. Increasing amount of catalyst in the matrix system improves electrical resistivity. Adding particles to matrix systems has a slight effect on different properties.

Two-phase Hybrid Thermal Interface Alkali-treated E-Glass Fiber/MWCNT/Graphene/Copper Oxide Nanocomposites for Electronic Gadgets.

Two-phase hybrid mode thermal interface materials were created and characterized for mechanical properties, thermal conductivity, and wear behaviour. Therefore, the ultimate goal of this current research was to use alkali-treated glass fibre and other allotropes to produce high-performance two-phase thermal interface materials. Three different polymer composites were prepared to contain 20 vol.% alkalies [NaOH] treated e-glass fibre [E] and epoxy as a matrix with varying proportions of multi-walled carbon nanotube [MWCNT], graphene [G], copper oxide [C]. The one-phase material contained epoxy+20%e-glass+1%MWCNT [EMGC1], the two-phase hybrid composite contained epoxy+20%e-glass+1%MWCNT+1%graphene+1%CuO [EMGC2], and two-phase material contained epoxy+20%e-glass+1%graphene+1%CuO [EMGC3]. Vacuum bagging method was used for fabricating the composites. The higher thermal conductivity observed was 0.3466 W/mK for EMGC2, the alkali-treated glass fibre/hybrid mode nanofillers epoxy matrix composite was mechanically tougher than the other two composites [EMGC1 & EMGC3]. Scanning electron microscopy analysis revealed the fine filler dispersion and homogenous interaction with the glass fibre/epoxy resin composite of the upper and lower zone, which also revealed the defective zone, fibre elongation, fibre/filler breakages, and filler leached surfaces. Finally, it was concluded that the hybrid mode two-phased structure EMGC2 epoxy matrix composite replicated the maximum thermal conductivity, mechanical properties, and wear properties of the other two specimens.

Effect of Chitin Nanocrystal Deacetylation on a Nature-Mimicking Interface in Carbon Fiber Composites

The formation of a rigid, tough interface based on a nacre-like structure in carbon fiber (CF) composites is a promising way to eliminate low delamination resistance. An effective method of coating CFs is electrophoretic deposition (EPD), which, in the case of dissimilar components like graphene oxide (GO) and polymeric glue, usually requires chemical bonding/strong interactions. In this work, we focus on chitin nanocrystals (ChNCs), leading to an excellent mechanical performance of artificial nacre, where favorable interactions and bonding with GO are controlled by degrees of deacetylation (5, 15, and 30%). We prepared coatings based on GO/ChNC adducts with 95/5, 90/10, 50/50, and 25/75 ratios using optimized EPD conditions (pH, concentration, voltage, and time). The prepared materials were characterized using FTIR, TEM, XPS, SEM, DLS, and XRD. SEM evaluation indicates the formation of a homogeneous interlayer, which has a fair potential for chemical bonding with the epoxy matrix. Short-beam testing of epoxy matrix composites indicates that the coating does not decrease stiffness and has a relatively low dependence on composition. Therefore, all coatings are promising for a detailed study of delamination resistance using laminate samples. Moreover, facile EPD from the water solution/suspension has a fair potential for industrial applications.

Mechanical properties: Lifespan and retention forecast for jute fiber woven fabric reinforced epoxy matrix composite

AbstractPolymer composites bonded with natural fibers are extensively used for a range of engineering purposes. Preserving their mechanical strength and estimating their maximum service life are thus essential for efficient usage. The primary goals of this effort are to analyze and forecast the longest possible life span of composites. To do this, Fick's law and the Arrhenius principle are employed to analyze the diffusion coefficient and activation energy. Compression molding technology and a manual technique for layup were employed to make the composites reinforced with epoxy laminate and woven mats of jute fiber (JRC). Three layering patterns were used to prepare the laminated composite: 45° angle‐ply laminate [0°/+45°/0°/−45°/0°], 0° balanced laminate [0°/0°/0°/0°/0°/0°], and 30° angle‐ply laminate [0°/+30°/0°/−30°/0°]. In order to examine how aging affected the composites' mechanical properties, the materials were immersed in water for 10, 20, 30, and 40 days throughout the study. The study's conclusions showed that the composite samples' weight rose with age. It was possible to make precise predictions about strength retention by comparing the mechanical characteristics of aged (wet) and unaged composites. It was discovered that the strongest composites were those with a 45‐degree stacking pattern. The activation energy of composites with a 45° angle‐ply laminate layering pattern is maximum, according to the Arrhenius principle. Additionally, using an electron microscope with scanning capabilities (SEM), it was possible to determine the fiber matrix and the tensile cracked surface contact connection.Highlights The widespread usage of polymer composites with natural fibers in engineering applications. Preservation of mechanical strength and predicting the maximum service life of these composites show how important these materials are for engineering efficiency. Fick's rule and the Arrhenius principle are used to analyze diffusion coefficient and activation energy. Laminated composites are made using 45° angle‐ply, 0° balanced laminate, and 30° angle‐ply layering patterns. The impact of simulated aging on composite mechanical characteristics by water immersion for varied periods.

Impact of the Curing Temperature on the Manufacturing Process of Multi-Nanoparticle-Reinforced Epoxy Matrix Composites.

This study aims to analyze the effect of the curing temperature of nano-reinforcements during the manufacturing process on the mechanical properties of composites involving graphene (GNP), carbon nanofibers (CNFs), and a hybrid mixture of these two nanoparticles. In this context, the type of nanoparticles, their content, their type of resin, and their hybridization were considered. The results showed that both nanoparticles increased the viscosity of the resin suspension, with an increase of between 16.3% and 38.2% for GNP nanoparticles and 45.4% and 74% for CNFs depending on the type of resin. Shrinkage was also affected by the addition of nanoparticles, as the highest results were obtained with GNP nanoparticles, with a 91% increase compared with the neat resin, and the lowest results were obtained with CNFs, with a decrease of 77% compared with the neat resin. A curing temperature of 5 °C promoted the best bending and hardness performance for all composites regardless of the type of resin and reinforcement used, with improvements of up to 24.8% for GNP nanoparticles and 13.52% for CNFs compared with the neat resin at 20 °C. Hybridization led to further improvements in bending properties and hardness compared with single-reinforcement composites due to a synergistic effect. However, the effectiveness of hybridization depends on the type of resin.

Fabrication and Mechanical Testing of Glass Fiber Reinforced Epoxy Matrix Composites Modified with Powdered Metallic Fillers

Composite materials made up of polymer matrix reinforced with synthetic fibers have gained popularity of late owing to their enhanced mechanical properties. However, very little work is reported to date on metals being used as filler material. Research gaps were obtained pertaining to the use of metallic fillers in synthetic fiber reinforced polymer composites. This paper demonstrates an attempt to fabricate composites made of Epoxy polymer matrix and E-glass fiber reinforcement with Mild Steel in its powdered form as fillers. Composites are prepared in varying weight percentages of the filler in the order of 2 wt. %, 4 wt. % and 6 wt. %. Hand layup method is employed for fabricating these composites which are later subjected to compression. Further, the samples are machined according to ASTM D3039 standard for tensile test and ASTM D256 standard for Izod impact test. Hardness test is also performed using a Shore D Durometer and these properties are compared with the unfilled samples. The results indicated that the weight percentage of the filler clearly influenced the mechanical properties of the developed composites. This study also revealed that the hardness and tensile strength of these composites improved with the incorporation of fillers up to 2 wt. % whereas, the impact strength improved up to 4 wt. %. Thereafter, there was a decline in their impact and tensile properties. However, hardness marginally increased beyond 4 wt. %. This area is open for research with regard to their usability under tribological, high temperature or magnetic conditions.

Mechanical and Ballistic Properties of Epoxy Composites Reinforced with Babassu Fibers (Attalea speciosa).

The mechanical and ballistic performance of epoxy matrix composites reinforced with 10, 20, and 30 vol.% of babassu fibers was investigated for the first time. The tests included tension, impact, and ballistic testing with 0.22 caliber ammunition. The results showed an improvement in tensile strength, elastic modulus, and elongation with the addition of babassu fiber, and the 30 vol.% composite stood out. Scanning electron microscopy analysis revealed the fracture modes of the composites, highlighting brittle fractures in the epoxy matrix, as well as other mechanisms such as fiber breakage and delamination in the fiber composites. Izod impact tests also showed improvement with increasing babassu fiber content. In ballistic tests, there was an increase in absorbed energy. All composites surpassed plain epoxy by over 3.5 times in ballistic energy absorption, underscoring the potential of babassu fiber in engineering and defense applications.

A comprehensive investigation on tensile behavior of surface‐modified Kevlar hybrid nanocomposites for similar and dissimilar joints

AbstractThe main objective of this study is to enhance the interfacial adhesion between Kevlar fiber‐reinforced epoxy composite for a single lap joint. This has been achieved by performing various chemical treatments on Kevlar fiber. Moreover, the nanofiller‐added epoxy matrices were also used for investigating its potentiality in a single lap joint. A thorough comparison has been made among various chemical treatments based composite and modified epoxy matrix composite. The tensile strength of similar and dissimilar single lap joints was investigated through experiments and was analyzed by SEM, XRD, and Weibull model. It was perceived that the tensile shear strength and Weibull modulus of the treated similar Kevlar lap joint were 21.45% and 40.18% higher than the similar nanocomposite joint; also, it has been found that an increment of about 79.8% and 76.64% with that of untreated similar Kevlar joint. Furthermore, the failure progression of optimized joints was evaluated by acoustic emission (AE) monitoring.Highlights Interfacial adhesion study of Kevlar fiber with matrix in single lap joint. Kevlar surface modification and epoxy modified by nanocomposites were used. The lap shear strength of similar and dissimilar single lap joint composites. SEM, XRD, and Weibull analysis and AE monitoring were used for this research. Chemical treatments on Kevlar fiber have enhanced the interfacial adhesion.