scholarly journals THE CONCEPT OF MULTI-LEVEL MODIFICATION IN THE TECHNOLOGY OF HIGHLY FILLED FLUOROCOMPOSITES

2021 ◽  
Vol 2 (11(75)) ◽  
pp. 25-31
Author(s):  
S. Avdeychik ◽  
A. Antonov ◽  
A. Lesun
Keyword(s):  
Tensile Strength ◽  
Composite Materials ◽  
Carbon Fiber ◽  
Negative Impact ◽  
Interfacial Interaction ◽  
Technological Paradigm ◽  
Interfacial Phase ◽  
Multi Level ◽  
Degree Of Filling ◽  
Deformation And Strength Characteristics

The structural and technological aspects of obtaining composite materials based on polytetrafluoroethylene are considered. It is shown that due to the existence of inert components in the process of interfacial interaction with the degree of filling in the traditional technological paradigm implemented, structural paradox manifests itself in proportion to the reduction of the parameter of tensile strength with increasing degree of filling. According to the concept of multi-level modification, the technological principles are proposed to eliminate the negative impact of the structural paradox fluorine composites by controlling the structure of the organization at various levels – molecular, supramolecular, and interfacial phase. Efficient methods of manufacture of products from highly filled fluorine composites containing 25–35 wt. % carbon fiber with parameters of deformation and strength characteristics higher than the corresponding parameters of analogs.

Evaluating the Mechanical Properties of Carbon Fiber Reinforced Polymer Matrix Composite Materials at Room and Elevated Temperatures

2012 ◽  
Author(s):  
Mahdi Farahikia ◽  
Sunilbhai Macwan ◽  
Fereidoon Delfanian ◽  
Zhong Hu
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Composite Materials ◽  
Carbon Fiber ◽  
Room Temperature ◽  
Polymer Matrix Composite ◽  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Shear Tests ◽  
Reinforced Polymer

A series of tensile, compression and shear tests in room temperature were carried out on carbon fiber reinforced polymer matrix composite materials (IM7/PEEKEK) to evaluate their mechanical properties. Also tensile tests at 160 degrees Fahrenheit (72 degrees Celsius) in longitudinal and transverse directions were done to study the effects of such temperature on the tensile strength of the mentioned composite materials. The setup of the testing equipment and the furnace that was used to provide elevated temperature conditions limited the possibility of conducting compressive and shear tests at high temperature as well as raising the temperature to higher levels. The experiments were set up in accordance with ASTM standards that best corresponded to the test specifications. Specimens were categorized into groups according to their nature of testing. All the specimens were reinforced at both ends by means of tabs which were bonded on both faces to reduce the effects of the external pressure exerted on them through the grips of the testing machines and were tested until failure. Load, elongation (displacement) and strain data were recorded by means of strain gages and data acquisition systems. The accuracy of the experimental data for the room temperature portion of the experiments is verified by comparing them to those of the most equivalent composite family, as having not been given any information regarding the structural properties and manufacturing processes of the composite materials that were used throughout the experiments made it difficult to find exact ASTM standards and reference materials for the testing and comparison of results. The results of the experiments showed that the tensile strength of this particular composite material is not effected by the 160 degrees Fahrenheit temperature; a point that is proved by the literature indicating their specific and sensitive application in aircraft heat dissipation [1].

Strength of carbon fiber/epoxy in sea water

2021 ◽  
Vol 63 (9) ◽  
pp. 811-815
Author(s):  
Ercüment Uğur Yüncüoğlu ◽  
Serdar Turgut Ince ◽  
Eyup Bağcı
Keyword(s):  
Tensile Strength ◽  
Composite Materials ◽  
Carbon Fiber ◽  
Sea Water ◽  
Matrix Material ◽  
Orientation Angle ◽  
Number Of Layers ◽  
Marine Industry ◽  
The Matrix ◽  
Negative Effect

Abstract Composite materials are widely used in the marine industry. The marine environment, on the other hand, has a significant impact on the strength of composite materials. The tensile strength is adversely affected because the matrix material absorbs water. In this study, the effect of orientation, number of layers and different mediums over time on the tensile strength of the woven carbon fiber reinforced epoxy composite material was investigated experimentally from a comprehensive perspective. The findings of the experiments were subjected to variance analysis. The repeated tests and cross-results of the experimental parameters were found to be compatible with each other. Seawater reduces the tensile strength of composite materials in any case. The tensile strength increased with increasing the number of layers. However, it has been observed that the seawater medium reduces strength when the number of layers increases. At the same time, as orientation angle rises, the seawater medium’s negative effect on strength rises.

scholarly journals Comparative Analysis Of Mechanical Properties Of Rubber-Kenaf-Wire-Cotton Lamination On Epoxy-Carbon-Ramie Composite

2020 ◽  
Vol 3 (2) ◽  
Author(s):  
I Komang Astana Widi
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Composite Materials ◽  
Carbon Fiber ◽  
Impact Strength ◽  
Volume Fraction ◽  
Ramie Fiber ◽  
Kenaf Fiber ◽  
Wire Specimen ◽  
The Impact

The use of fiber has been widely researched but the use of several fibers as reinforcement does not necessarily result in optimal mechanical properties. This study aimed to determine the tensile strength and impact strength of composite materials using an epoxy matrix with the addition of rubber variations to increase the ductility of the matrix. Meanwhile, the fibers used for reinforcement are carbon fiber and ramie. In this study, the reinforcement added a variety of kenaf fiber, wire and cotton. This was to compare the role of kenaf fiber, wire and cotton in improving the mechanical properties of composite materials. The percentage of rubber volume fraction added to the epoxy is 30%, 40% and 50%.The highest tensile test results were shown in the 30% epoxy rubber-carbon fiber-ramie fiber-kenaf specimen which was 10.67 Kgf / mm2, and the lowest result was the epoxy 50% rubber-carbon fiber-ramie-wire specimen, which was 5.752 kgf / mm2. The fracture analysis of the tensile test showed that the fracture area is formed by debonding phenomena between fibers and matrices.The highest impact strength was found in the 50% epoxy rubber-carbon fiber-ramie-wire specimen, which was 0.039 kgf / mm2. Meanwhile, the lowest impact strength was found in the 40% epoxy rubber-carbon fiber-ramie fiber-cotton specimen, which was 0.030 kgf/ mm2. In general, the trend of impact test data shows that as the percentage volume fraction of rubber increases, the impact strength of the composite material increases.Based on the test analysis, it was concluded that increasing the percentage of rubber will increase the impact strength of the woven wire reinforcement. However, the impact strength is inversely proportional to kenaf fiber reinforcement, where the addition of the percentage of rubber will reduce the impact strength. This showed that the mechanical properties were not always influenced by the percentage of rubber but were very dependent on the type of fiber. This was also shown in the results of the tensile strength test. In general, it was known that the adhesion between fiber and matrix laminates affected the mechanical properties in addition to the strength of the reinforcement.

scholarly journals Absorption and Strength Properties of Short Carbon Fiber Reinforced Mortar Composite

Buildings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 300
Author(s):  
Md. Safiuddin ◽  
George Abdel-Sayed ◽  
Nataliya Hearn
Keyword(s):  
Tensile Strength ◽  
Carbon Fiber ◽  
Water Absorption ◽  
Carbon Fibers ◽  
Strength Properties ◽  
Fiber Content ◽  
Test Results ◽  
Air Content ◽  
Entrapped Air ◽  
Short Carbon

This paper presents the water absorption and strength properties of short carbon fiber reinforced mortar (CFRM) composite. Four CFRM composites with 1%, 2%, 3%, and 4% short pitch-based carbon fibers were produced in this study. Normal Portland cement mortar (NCPM) was also prepared for use as the control mortar. The freshly mixed mortar composites were tested for workability, wet density, and entrapped air content. In addition, the hardened mortar composites were examined for compressive strength, splitting tensile strength, flexural strength, and water absorption at the ages of 7 and 28 days. The effects of different carbon fiber contents on the tested properties were observed. Test results showed that the incorporation of carbon fibers decreased the workability and wet density, but increased the entrapped air content in mortar composite. Most interestingly, the compressive strength of CFRM composite increased up to 3% carbon fiber content and then it declined significantly for 4% fiber content, depending on the workability and compaction of the mortar. In contrast, the splitting tensile strength and flexural strength of the CFRM composite increased for all fiber contents due to the greater cracking resistance and improved bond strength of the carbon fibers in the mortar. The presence of short pitch-based carbon fibers significantly strengthened the mortar by bridging the microcracks, resisting the propagation of these minute cracks, and impeding the growth of macrocracks. Furthermore, the water absorption of CFRM composite decreased up to 3% carbon fiber content and then it increased substantially for 4% fiber content, depending on the entrapped air content of the mortar. The overall test results suggest that the mortar with 3% carbon fibers is the optimum CFRM composite based on the tested properties.

scholarly journals High Mechanic Enhancement of Chopped Carbon Fiber Reinforced-Low-Density Unsaturated Polyester Resin Composite at Low Preparation Temperature with Facile Polymerization

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4273
Author(s):  
Jian Zhang ◽  
Xiaojun Wang ◽  
Xinjun Fu
Keyword(s):  
Composite Materials ◽  
Carbon Fiber ◽  
Low Temperature ◽  
Surface Defect ◽  
Polyester Resin ◽  
Unsaturated Polyester ◽  
Unsaturated Polyester Resin ◽  
Low Density ◽  
Fiber Reinforced ◽  
Preparation Temperature

Chopped carbon fiber-reinforced low-density unsaturated polyester resin (CCFR-LDUPR) composite materials with light weight and high mechanical properties were prepared at low temperature and under the synergistic action of methyl ethyl ketone peroxide (MEKP-II) and cobalt naphthenate. Optimal preparation conditions were obtained through an orthogonal experiment, which were preparation temperature at 58.0 °C, 2.00 parts per hundred of resin (phr) of NH4HCO3, 4.00 phr of chopped carbon fibers (CCFs) in a length of 6.0 mm, 1.25 phr of initiator and 0.08 phr of cobalt naphthenate. CCFR-LDUPR composite sample presented its optimal properties for which the density (ρ) was 0.58 ± 0.02 g·cm−3 and the specific compressive strength (Ps) was 53.56 ± 0.83 MPa·g−1·cm3, which is 38.9% higher than that of chopped glass fiber-reinforced low-density unsaturated polyester resin (CGFR-LDUPR) composite materials. Synergistic effects of initiator and accelerator accelerated the specific polymerization of resin in facile preparation at low temperature. Unique “dimples”, “plate microstructure” and “surface defect” fabricated the specific microstructure of the matrix of CCFR-LDUPR composite samples, which was different from that of cured unsaturated polyester resin (UPR) with “body defect” or that of CGFR-LDUPR with coexistence of “surface defect” and “body defect”.

Effects of Accelerated Aging Period of Time at 180°C on Tensile Property of Plain Woven Fabric/Epoxy Resin Laminated Composites

2012 ◽  
Vol 182-183 ◽  
pp. 76-79 ◽  
Author(s):  
Lei Lei Song ◽  
Quan Rong Liu ◽  
Jia Lu Li
Keyword(s):  
Tensile Strength ◽  
Carbon Fiber ◽  
Epoxy Resin ◽  
Laminated Composites ◽  
Accelerated Aging ◽  
Woven Fabric ◽  
Accelerated Ageing ◽  
Time Intervals ◽  
Composite Samples

In this paper, carbon fiber reinforced resin matrix composites were produced by stacking eight pieces of carbon fiber woven plain fabric and subjected to accelerated ageing. Accelerated ageing was carried out in oven at 180°C for three different time intervals (60 hours, 120 hours and 180 hours). The influence of different ageing time intervals at 180°C on tensile properties of laminated composites was examined, compared with the composites without aging. The appearance and damage forms of these laminated composites were investigated. The results revealed that the tensile strength of the laminates declined significantly after long term accelerated aging at 180°C. The average tensile strengths of composite samples aged 60 hours, 120 hours, and 180 hours period of time at 180°C are 80.36%, 79.82%, 76.57% of average tensile strength of composite samples without aging, respectively. The high temperature accelerated aging makes the resin macromolecular structure in the composites changed, and then the adhesive force between fiber bundles and resin declines rapidly which result in the tensile strength of composites aged decrease. This research provides a useful reference for long term durability of laminated/epoxy resin composites.

Fabrication and Research of Electroless Nickel Plating on Carbon Fiber with Palladium-Free Activation

2010 ◽  
Vol 148-149 ◽  
pp. 410-415
Author(s):  
Xiao Ping Luo ◽  
Ming Gang Zhang ◽  
Chun Xiang Lv
Keyword(s):  
Tensile Strength ◽  
Carbon Fiber ◽  
Fiber Surface ◽  
Electroless Nickel ◽  
Electroless Nickel Plating ◽  
Nickel Plating ◽  
Adhesive Properties ◽  
Nickel Deposition ◽  
X Ray ◽  
Electroless Ni

A new procedure of surface activation without using palladium salt is proposed for electroless nickel plating (Ni-P) on carbon fiber. The optimal formula and technical conditions for palladium-free activated electroless Ni-P were obtained by orthogonal experiments. The effects of nitric acid processing time on the quality of nickel coating was investigated .The effects of varying concentrations of Ni2 + on the rate of weight gain during the Ni2 + complex adsorption process were also analyzed and the kinetic equation of the process was established. The theoretical values calculated by the equation were proven to be consistent with the experimental verification. The material characteristics of the deposited layers were analyzed by scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDX) and X-ray diffraction (XRD). The tensile strength of the carbon fibers was analyzed by the Weibull method, and this showed that when the thickness of the Ni-P coating reached 0.150μm, the tensile strength reached a maximum value. The experimental results showed that the nickel deposition on the carbon fiber surface obtained by this method, had the same uniformity, compactness and adhesive properties as the one by conventional electroless Ni-P.

Sign in / Sign up

Export Citation Format

Share Document