scholarly journals Influence of microfillers addition on the flexural properties of carbon fiber reinforced phenolic composites

2021 ◽  
pp. 002199832110316
Author(s):  
IA Abdulganiyu ◽  
INA Oguocha ◽  
AG Odeshi

The effects of microfiller addition on the flexural properties of carbon fiber reinforced phenolic (CFRP) matrix composites were investigated. The CFRP was produced using colloidal silica and silicon carbide (SiC) microfillers, 2 D woven carbon fibers, and two variants of phenolic resole (HRJ-15881 and SP-6877). The resins have the same phenol and solid content but differ in their viscosities and HCHO (formaldehyde) content. The weight fractions of microfillers incorporated into the phenolic matrix are 0.5 wt.%, 1 wt.%, 1.5 wt.%, and 2 wt.%. Flexural properties were determined using a three-point bending test and the damage evolution under flexural loading was investigated using optical and scanning electron microscopy. The results indicated that the reinforcement of phenolic resins with carbon fibers increased the flexural strength of the HRJ-15881 and SP-6877 by 508% and 909%, respectively. The flexural strength of the CFRP composites further increased with the addition of SiC particles up to 1 wt.% SiC but decreased with further increase in the amount of SiC particles. On the other hand, the flexural modulus of the CFRP composites generally decreased with the addition of SiC microfiller. Both the flexural strength and flexural modulus of the CFRP did not improve with the addition of colloidal silica particles. The decrease in flexural properties is caused by the agglomeration of the microfillers, with colloidal silica exhibiting more tendency for agglomeration than SiC. The fractured surfaces revealed fiber breakage, matrix cracking, and delamination under flexural loading. The tendency for failure worsened at microfiller addition of ≥1.5 wt.%.

2012 ◽  
Vol 224 ◽  
pp. 199-203
Author(s):  
Xiang Hong Zhang ◽  
Han Yang ◽  
Hao Zhang ◽  
Chun Yang Wang

In this study, nylon PA6 resin was filled with carbon fibers by employing the technique of mechanical alloying and utilizing the special properties of carbon fiber. The effects of carbon fiber on the mechanical property of the nylon PA6 were also studied. From the results, filling nylon PA6 resin with carbon fiber could effectively enhance the tensile strength, the elastic modulus, the flexural strength and the flexural modulus for the material. In addition, the material shrinkage was also significantly reduced. The enhancing effects varied as CF content changed. Through comparative experiments, the optimal proportion of the addition was determined. Replacing the conventional irony back pad of military outdoor pot by this composite would not only largely reduce the load and improve the motility for the soldiers, but also ensure a better battlefield adaptability and comfort.


2018 ◽  
Vol 225 ◽  
pp. 01022
Author(s):  
Falak O. Abasi ◽  
Raghad U. Aabass

Newer manufacturing techniques were invented and introduced during the last few decades; some of them were increasingly popular due to their enhanced advantages and ease of manufacturing over the conventional processes. Polymer composite material such as glass, carbon and Kevlar fiber reinforced composite are popular in high performance and light weight applications such as aerospace and automobile fields. This research has been done by reinforcing the matrix (epoxy) resin with two kinds of the reinforcement fibers. One weight fractions were used (20%) wt., Epoxy reinforced with chopped carbon fiber and second reinforcement was epoxy reinforced with hybrid reinforcements Kevlar fiber and improved one was the three laminates Kevlar fiber and chopped carbon fibers reinforced epoxy resin. After preparation of composite materials some of the mechanical properties have been studied. Four different fiber loading, i.e., 0 wt. %, 20wt. % CCF, 20wt. % SKF, AND 20wt. %CCF + 20wt. % SKF were taken for evaluating the above said properties. The thermal and mechanical properties, i.e., hardness load, impact strength, flexural strength (bending load), and thermal conductivity are determined to represent the behaviour of composite structures with that of fibers loading. The results show that with the increase in fiber loading the mechanical properties of carbon fiber reinforced epoxy composites increases as compared to short carbon fiber reinforced epoxy composites except in case of hardness, short carbon fiber reinforced composites shows better results. Similarly, flexural strength test, Impact test, and Brinell hardness test the results show the flexural strength, impact strength of the hybrid composites values were increased with existence of Kevlar fibers, while the hardness was decrease. But the reinforcement with carbon fibers increases the hardness and decreases other tests.


Author(s):  
Aditya R. Thakur ◽  
Ming C. Leu ◽  
Xiangyang Dong

Abstract A new additive manufacturing (AM) approach to fabricate long fiber reinforced composites (LFRC) was proposed in this study. A high deposition rate was achieved by the implementation of a single-screw extruder, which directly used thermoplastic pellets and continuous fiber tows as feedstock materials. Thus, the proposed method was also used as a large-scale additive manufacturing (LSAM) method for printing large-volume components. Using polylactic acid (PLA) pellets and continuous carbon fiber tows, the feasibility of the proposed AM method was investigated through printing LFRC samples and further demonstrated by fabricating large-volume components with complex geometries. The printed LFRC samples were compared with pure thermoplastic and continuous fiber reinforced composite (CFRC) counterparts via mechanical tests and microstructural analyses. With comparable flexural modulus, the flexural strength of the LFRC samples was slightly lower than that of the CFRC samples. An average improvement of 28% in flexural strength and 50% in flexural modulus were achieved compared to those of pure PLA parts, respectively. Discontinuous long carbon fibers, with an average fiber length of 20.1 mm, were successfully incorporated into the printed LFRC samples. The carbon fiber orientation, distribution of carbon fiber length, and dispersion of carbon fiber as well as porosity were further studied. The carbon fibers were highly oriented along the printing direction with a relatively uniformly distributed fiber reinforcement across the LFRC cross section. With high deposition rate (up to 0.8 kg/hr) and low material costs (< $10/kg), this study demonstrated the potentials of the proposed printing method in LSAM of high strength polymer composites reinforced with long carbon fibers.


2004 ◽  
Vol 5 (2) ◽  
pp. 14-26 ◽  
Author(s):  
Lippo V.J. Lassila ◽  
Pekka K. Vallittu

Abstract The aim of this study was to investigate the influence of the position of the fiber rich layer on the flexural properties of fiber-reinforced composite (FRC) construction. In addition, the total residual monomer content of FRC was quantitatively determined to find out the difference of the effectiveness of two types of light-curing units using liquid chromatography (HPLC). Unidirectional continuous E-glass FRC and hybrid particulate filler composite resins were used in the fabrication of test specimens. Four different positions of the FRC layer were used: compression, neutral, tension, and vertical side position. A three-point bending test (ISO 10477) was performed to measure the flexural properties of the specimens. Position of the FRC layer had a significant effect on the flexural strength (p<0.001, ANOVA). Also, the type of light-curing device had an effect on flexural strength (p<0.001). Specimens with FRC positioned on the compression side showed flexural strength of approximately 250 MPa, whereas FRC positioned on the tension side showed strength ranging from 500 to 600 MPa. Mean flexural modulus with FRC placed horizontally ranged between 9-12 GPa; no significant difference was found between these groups. However when fiber reinforcement was positioned vertically, the flexural modulus raised up to 16 GPa. Specimens with 24 vol% glass fibers contained 52% less residual monomer than specimens without glass fibers. The monomer content was lower in specimens polymerized with the curing device with higher polymerization temperature. In order to optimize flexural strength of low fiber volume fraction, the fibers should be placed at the tension side of the specimen. Citation Lassila LVJ, Vallittu PK. The Effect of Fiber Position and Polymerization Condition on the Flexural Properties of Fiber-Reinforced Composite. J Contemp Dent Pract 2004 May;(5)2:014-026.


2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Gwang-Hee Heo ◽  
Jong-Gun Park ◽  
Ki-Chang Song ◽  
Jong-Ho Park ◽  
Hyung-Min Jun

In the present study, SiO2 particles were coated on the surface of carbon fibers by means of chemical reaction of silane coupling agent (glycidoxypropyl trimethoxysilane, GPTMS) and colloidal SiO2 sol to improve the interfacial bonding force between fibers and matrix in cement matrix. The surface of the modified carbon fibers was confirmed through a scanning electron microscope (SEM). The mechanical properties of SiO2-coated carbon fiber mortar and uncoated carbon fiber mortar with different fiber lengths (6 mm and 12 mm) and fiber volume fractions (0.5%, 1.0%, 1.5%, and 2.0%) were compared and analyzed. The experimental results show that the flow values of the carbon fiber mortar were greatly disadvantageous in terms of fluidity due to the nonhydrophilicity of fibers and fiber balls, and the unit weight decreased significantly as the fiber volume fractions increased. However, the air content increased more or less. In addition, regardless of whether the fibers were coated, the compressive strength of carbon fiber-reinforced mortar (CFRM) composite specimens tended to gradually decrease as the fiber volume fractions increased. On the other hand, in case of the SiO2-coated CFRM composite specimens, the flexural strength was significantly increased compared to uncoated CFRM composite specimens and plain mortar specimens, and the highest flexural strength was obtained at 12 mm and 1.5%, particularly. It can be seen that the new carbon fiber surface modification method employed in this study was very effective in enhancing the flexural strength as cement-reinforcing materials.


2015 ◽  
Vol 816 ◽  
pp. 152-156
Author(s):  
Xin Ma ◽  
Xin Bo He ◽  
Hai Feng Hu ◽  
Yu Di Zhang ◽  
Yong Li

2D Cf/SiC composites were prepared by precursor infiltration and pyrolysis (PIP) process with spreaded T700-12K plain weave carbon clothes as the reinforcement. The mechanical properties and microstructures were investigated. The composites are compact with few internal defects since the precursor could infiltrate the preform effectively. CVD-PyC interface modified the surface of T700 carbon fiber, a rough surface is helpful for the interfacial combination and the load transfer. For the Cf/PyC/SiC composites, the flexural strength and flexural modulus were 425±23.2 MPa and 36.3±3.1 GPa, respectively.


2019 ◽  
Vol 809 ◽  
pp. 41-46
Author(s):  
Franz Habla ◽  
M. Kropka ◽  
M. Muehlbacher ◽  
T. Neumeyer ◽  
Volker Altstädt

In this study, the quality of pre-consolidation of a PA6 based glass/carbon hybrid and a glass mono-material UD-tape laminate has been analyzed and the influence of the pre-consolidation step on flexural properties of end-consolidated laminates was determined. For this reason, three different pre-consolidation qualities were mechanically and optically analyzed. The investigations show that the quality of pre-consolidation is not critical for mono-material lay-ups considered in this work. However, the pre-consolidation step has a significant effect on the flexural properties of the hybrid-material laminate presented in this work. The flexural modulus is increased by more than 25 % and the flexural strength up to 9 % due to better welding of the distinct layers. Additionally, the influence of carbon fiber share on the flexural modulus of the UD hybrid-material was examined. It could be recognized that the flexural modulus can be increased up to 171 % by the exchange of glass with carbon fiber layers with a sandwich stacking compared to glass mono-material with constant thickness.


2019 ◽  
Vol 809 ◽  
pp. 335-340
Author(s):  
Mathias Czasny ◽  
Oliver Goerke ◽  
Onur Kaba ◽  
Stephan Koerber ◽  
Franziska Schmidt ◽  
...  

Additive manufacturing of endless carbon fiber-reinforced composites is a technology which produces parts with mechanical properties similar to those of additively-manufactured metallic parts. In this work, the influence of layer height and width on mechanical properties of additively-manufactured carbon fiber-reinforced polymer composites has been studied. Two different 3k carbon fibers have been used as reinforcement. The composites are printed by material extrusion technology with layer heights of 0.2, 0.3, and 0.4 mm and layer widths of 1.0, 1.2, and 1.7 mm. The composites possess higher flexural strength at smaller layer height and the flexural modulus is dependent on the fiber volume content. The formation of voids/defects decreases the mechanical properties of composite and should be optimized.


2010 ◽  
Vol 434-435 ◽  
pp. 627-629 ◽  
Author(s):  
Juan Ying Li ◽  
Jian Feng Huang ◽  
Li Yun Cao

Carbon fiber reinforced silicon-substituted hydroxyapatite (C(f)/Si-HA) bone cements composites were prepared by microwave chemical reaction with a later solidification process using carbamide, calcium nitrate, ammonium dibasic phosphate and ethyl silicate as raw materials, and buffer solutions of acrylic acid and itaconic acid as gelling agent. The influences of carbon fibers volume fraction, contents of coupling agents, sodium citrate contents on the flexural strength of silicon- substituted hydroxyapatite bone cements composites were particularly investigated. The phase composition, microstructures and flexural strength of the composites were characterized by X-ray diffraction, scanning electron microscope and universal testing machine analyses. And the flexural strength of the prepared composites reach the maximum value 41.5MPa when the carbon fibers volume fraction, silane agent KH550 and sodium citrate mass fraction arrive to 3.0, 0.6 and 3.0%, respectively.


2020 ◽  
Vol 858 ◽  
pp. 72-77
Author(s):  
Abu Shaid Sujon ◽  
Tahamir Hasan Supto ◽  
Fahim Shariar ◽  
Md Mushfiqur Rahman Pallab ◽  
Mohammad Zoynal Abedin ◽  
...  

The consequence of placing a different layer of jute and carbon fiber in different position inside the composite has been experimentally investigated. Six layers of woven unidirectional jute fiber and four-layer of carbon fiber has been used with five different stacking sequences in this study. Vacuum Assisted Resin Infusion (VARI) technology has been used for the manufacturing of the composite. After analyzing the results of the tensile and flexural test of the composites, it shows that the stacking sequence has a significant effect on those properties of the composites. Tensile strength of the composites was upgraded when all the layers of carbon fiber were placed in the middle of the sandwich-like composite structure whereas flexural strength of the composites was improved when carbon fibers were placed on the compression and tension side of the composite.


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