scholarly journals Impact of Alternative Stabilization Strategies for the Production of PAN-Based Carbon Fibers with High Performance

Fibers ◽  
2020 ◽  
Vol 8 (6) ◽  
pp. 33 ◽  
Author(s):  
Spyridon Soulis ◽  
George Konstantopoulos ◽  
Elias P. Koumoulos ◽  
Costas A. Charitidis
Keyword(s):  
Mechanical Properties ◽  
Carbon Fibers ◽  
Thermal Processing ◽  
High Performance ◽  
Relevant Literature ◽  
Thermomechanical Properties ◽  
Composition Effect ◽  
Ladder Polymer ◽  
Fiber Manufacturing ◽  
Time And Energy

The aim of this work is to review a possible correlation of composition, thermal processing, and recent alternative stabilization technologies to the mechanical properties. The chemical microstructure of polyacrylonitrile (PAN) is discussed in detail to understand the influence in thermomechanical properties during stabilization by observing transformation from thermoplastic to ladder polymer. In addition, relevant literature data are used to understand the comonomer composition effect on mechanical properties. Technologies of direct fiber heating by irradiation have been recently involved and hold promise to enhance performance, reduce processing time and energy consumption. Carbon fiber manufacturing can provide benefits by using higher comonomer ratios, similar to textile grade or melt-spun PAN, in order to cut costs derived from an acrylonitrile precursor, without suffering in regard to mechanical properties. Energy intensive processes of stabilization and carbonization remain a challenging field of research in order to reduce both environmental impact and cost of the wide commercialization of carbon fibers (CFs) to enable their broad application.

Thermo-mechanical characterization of discontinuous recycled/repurposed carbon fiber reinforced thermoplastic organosheet composites

2021 ◽  
pp. 002199832110157
Author(s):  
Philip R Barnett ◽  
Stephen A Young ◽  
Vivek Chawla ◽  
Darren M Foster ◽  
Dayakar Penumadu
Keyword(s):  
Mechanical Properties ◽  
Carbon Fiber ◽  
High Performance ◽  
Thermomechanical Properties ◽  
Polyphenylene Sulfide ◽  
Single Fiber ◽  
Thermoplastic Resin ◽  
Scanning Calorimetry ◽  
Post Process ◽  
Process Annealing

The integration of repurposed and recycled carbon fibers into high-performance composites is essential to the adoption of composites for automotive structures due to their low-cost, high formability, and reduced environmental impact. When high areal density nonwovens of these fibers are infused with a semi-crystalline thermoplastic resin, organosheets offering competitive mechanical properties can be produced. This study examined the optimization of such composites through multiscale material characterization and post-process annealing. Single fiber tensile tests were used to characterize repurposed and recycled fiber formats. The thermomechanical properties of the polyphenylene sulfide matrix and resulting composites subjected to different post-process annealing conditions were characterized using differential scanning calorimetry, dynamic mechanical analysis, and nano-indentation. Single fiber push-in testing was conducted to evaluate the fiber–matrix interface as a function of annealing. It was shown that statistical methods based on the bootstrap principle successfully identify the effects of post-process annealing, which are otherwise masked by material inhomogeneity. Post-process annealing was shown to be an effective method of improving the resulting mechanical properties of repurposed and recycled carbon fiber organosheet composites, thereby optimizing their properties for use as a high-performance automotive structural material.

scholarly journals Mechanical Properties of a Unidirectional Basalt-Fiber/Epoxy Composite

2020 ◽  
Vol 4 (3) ◽  
pp. 101 ◽  
Author(s):  
David Plappert ◽  
Georg C. Ganzenmüller ◽  
Michael May ◽  
Samuel Beisel
Keyword(s):  
Mechanical Properties ◽  
Carbon Fibers ◽  
High Performance ◽  
Glass Fibers ◽  
Basalt Fiber ◽  
Fiber Composites ◽  
Basalt Fibers ◽  
Strength And Stiffness ◽  
Better Than

High-performance composites based on basalt fibers are becoming increasingly available. However, in comparison to traditional composites containing glass or carbon fibers, their mechanical properties are currently less well known. In particular, this is the case for laminates consisting of unidirectional plies of continuous basalt fibers in an epoxy polymer matrix. Here, we report a full quasi-static characterization of the properties of such a material. To this end, we investigate tension, compression, and shear specimens, cut from quality autoclave-cured basalt composites. Our findings indicate that, in terms of strength and stiffness, unidirectional basalt fiber composites are comparable to, or better than epoxy composites made from E-glass fibers. At the same time, basalt fiber composites combine low manufacturing costs with good recycling properties and are therefore well suited to a number of engineering applications.

scholarly journals Thermomechanical Properties of KevlarTM Reinforced Benzoxazine-Urethane Alloys

2013 ◽  
Vol 13 (1) ◽  
pp. 11
Author(s):  
Rimdusit S Rimdusit S ◽  
Kasemsiri P. Kasemsiri P. ◽  
Okhawilai M. Okhawilai M.
Keyword(s):  
Mechanical Properties ◽  
High Performance ◽  
Loss Modulus ◽  
Flexural Modulus ◽  
Testing Machine ◽  
Impact Resistance ◽  
Mechanical Analysis ◽  
Thermomechanical Properties ◽  
Alloy Matrix ◽  
Wide Range

Ballistic armor is one of an important application which required high performance of fiber-reinforced polymer due to its outstanding specific mechanical properties. Therefore, KevlarTM reinforced benzoxazine-urethane alloys as ballistic impact resistance composites were developed in this research. The polybenzoxazine alloy composites were fabricated by compression molding at 200ºC and 5 MPa by a compression molder. The amount of urethane fraction in the alloy matrix was ranging from 0-40wt% while the fiber content was kept constant at 80wt%. The mechanical properties of the matrix alloys and their KevlarTM fiber composites were characterized by dynamic mechanical analysis and universal testing machine. The results revealed that storage modulus at room temperature of the composites was reduced from 16.82 GPa when using the neat polybenzoxazine as a matrix to the value of 11.89 GPa at 40wt% of urethane content in the alloy matrix. Moreover, the more urethane in the alloy matrix resulted in lower flexural modulus of the KevlarTM composites i.e. 22 GPa when using the neat polybenzoxazine as a matrix to the value of 12 GPa when using 40wt% of urethane in the alloy matrix. Interestingly, glass transition temperature (Tg) obtained from the maximum peak of the loss modulus was observed to be in the range of 187-247ºC, which was significantly higher than those of the two parent polymers. Furthermore, the activation energy of the alloys was found to increase with increasing urethane content, which corresponded to the observed Tg value enhancement. The observed synergism in Tg of KevlarTM reinforced benzoxazine-urethane was an outstanding characteristic for a wide range of applications, which requires high thermal stability.

scholarly journals Preparation and Characterization of Carbon Fibers from Lyocell Precursors Grafted with Polyacrylamide via Electron-Beam Irradiation

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2459
Author(s):  
Hong Gun Kim ◽  
Yong-Sun Kim ◽  
Yun-Su Kuk ◽  
Lee Ku Kwac ◽  
Sun-Ho Choi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Electron Beam ◽  
Carbon Fibers ◽  
Cross Sections ◽  
High Performance ◽  
Electron Beam Irradiation ◽  
High Viscosity ◽  
Beam Irradiation ◽  
Round Cross

Carbon fibers, which act as reinforcements in many applications, are often obtained from polyacrylonitrile (PAN). However, their production is expensive and results in waste problems. Therefore, we focused on producing carbon fibers from lyocell, a cellulose-based material, and analyzed the effects of the process parameters on their mechanical properties and carbon yields. Lyocell was initially grafted with polyacrylamide (PAM) via electron-beam irradiation (EBI) and was subsequently stabilized and carbonized. Thermal analysis showed that PAM grafting increased the carbon yields to 20% at 1000 °C when compared to that of raw lyocell, which degraded completely at about 600 °C. Stabilization further increased this yield to 55%. The morphology of the produced carbon fibers was highly dependent on PAM concentration, with fibers obtained at concentrations ≤0.5 wt.% exhibiting clear, rigid, and round cross-sections with smooth surfaces, whereas fibers obtained from 2 and 4 wt.% showed peeling surfaces and attachment between individual fibers due to high viscosity of PAM. These features affected the mechanical properties of the fibers. In this study, carbon fibers of the highest tensile strength (1.39 GPa) were produced with 0.5 wt.% PAM, thereby establishing the feasibility of using EBI-induced PAM grafting on lyocell fabrics to produce high-performance carbon fibers with good yields.

scholarly journals Single-step process to improve the mechanical properties of carbon nanotube yarn

2018 ◽  
Vol 9 ◽  
pp. 545-554 ◽  
Author(s):  
Maria Cecilia Evora ◽  
Xinyi Lu ◽  
Nitilaksha Hiremath ◽  
Nam-Goo Kang ◽  
Kunlun Hong ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotube ◽  
Carbon Fibers ◽  
Photoelectron Spectroscopy ◽  
High Performance ◽  
Single Step ◽  
Beam Irradiation ◽  
X Ray ◽  
Yarn Strength ◽  
Irradiation Process

Carbon nanotube (CNT) yarns exhibit low tensile strength compared to conventional high-performance carbon fibers due to the facile sliding of CNTs past one another. Electron beam (e-beam) irradiation was employed for in a single-step surface modification of CNTs to improve the mechanical properties of this material. To this end, CNT yarns were simultaneously functionalized and crosslinked using acrylic acid (AA) and acrylonitrile (AN) in an e-beam irradiation process. The chemical modification of CNT yarns was confirmed by X-ray photoelectron spectroscopy (XPS), Raman spectroscopy and scanning electron microscopy (SEM). The best improvement in mechanical properties was achieved on a sample treated with an aqueous solution of AA and subsequent irradiation. CNT yarn treatment with AA enhanced the strength (444.5 ± 68.4 MPa) by more than 75% and the modulus (21.5 ± 0.6 GPa) by more than 144% as compared to untreated CNT yarn (strength 251 ± 26.5 MPa and modulus 8.8 ± 1.2 GPa).

scholarly journals Epitaxial Grown Carbon Nanotubes Reinforced Pyrocarbon Matrix in C/C Composites with Improved Mechanical Properties

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6607
Author(s):  
Ningkun Liu ◽  
Gang Kou ◽  
Lingjun Guo ◽  
Yunyu Li ◽  
Xuemin Yin
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Carbon Fibers ◽  
Structural Design ◽  
High Performance ◽  
Rational Design ◽  
Raman Analysis ◽  
Precise Control ◽  
Highly Efficient ◽  
Large Size

In order to achieve the highly efficient preparation of high-performance carbon/carbon (C/C) composites, epitaxial grown carbon nanotubes (CNTs) and a pyrocarbon matrix were simultaneously synthesized to fabricate CNT-reinforced C/C composites (CC/C composites). With precise control of the temperature gradient, CNTs and the pyrocarbon matrix could grow synchronously within a 2D needle-punched carbon fiber preform. Surprisingly, the CNTs remained intact within the pyrocarbon matrix at the nano-level, and the CNT-reinforced nano-pyrocarbon matrix was compact, with virtually no gaps and pores, which were tightly connected with the carbon fibers without cracks. Based on the results of Raman analysis, there is less residual stress in the CNT-reinforced pyrocarbon matrix and carbon fibers, and less of a mismatch between the coefficient and thermal expansion. Additionally, CC/C composites fabricated by this method could achieve a low density, open porosity with a large size, and improved mechanical properties. More importantly, our work provides a rational design strategy for the highly efficient preparation and structural design of high-performance CNT-einforced C/C composites.

The characterization of high-performance PAN-based carbon fibers developed by continuous carbonization and air oxidation

1995 ◽  
Vol 10 (6) ◽  
pp. 1529-1538 ◽  
Author(s):  
Tse-Hao Ko ◽  
Chien-Hung Li ◽  
Chung-Hua Hu
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Carbon Fibers ◽  
High Performance ◽  
Optimum Conditions ◽  
Air Oxidation ◽  
Temperature Optimum ◽  
Oxidized Carbon ◽  
Oxidation Behaviors

The properties of four kinds of Type II carbon fibers, which had been precarbonized at 300 °C, 400 °C, 500 °C, and 600 °C, respectively, during two-stage continuous carbonization, were measured after being air oxidized for periods of 1 to 6 min at 550 °C. The effects of precarbonization temperature on mechanical properties, density, morphology, elemental composition, and microstructure of the carbon fibers during the air oxidation are discussed in this article. The precarbonization process strongly affected the surface properties and mechanical properties of the final oxidized carbon fibers. The carbon fibers developed from the different precarbonization temperatures all had different structures. The carbon fibers that had been precarbonized at 300 °C had a more ordered structure than other fibers after air oxidation. These carbon fibers also had a higher performance than the other fibers. Carbon fibers also showed different oxidation behaviors caused by differences in surface morphology resulting from each different precarbonization temperature. Optimum conditions not only improved the tensile strength and modulus, but also increased the density and oxygen content. Experimental results showed that the tensile strength of the carbon fibers precarbonized at 300 °C increased from 2.4 GPa to 4.3 GPa (80%) after 6 min oxidation at 550 °C.

Spray Forming and Thermal Processing for High Performance Superalloys

2005 ◽  
Vol 475-479 ◽  
pp. 2773-2778 ◽  
Author(s):  
Guo Qing Zhang ◽  
Zhou Li ◽  
Zhong Wu Liu ◽  
Zhi Hui Zhang ◽  
Yifei Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Processing ◽  
High Performance ◽  
Deposition Process ◽  
Spray Forming ◽  
Hot Workability ◽  
Forming Technology ◽  
Turbine Disks ◽  
New Processing ◽  
Rapidly Solidified

A unique pilot low-pressure spray forming plant was established and its spray atomisation and deposition process developed to study the new processing methods for high performance materials and to develop spray forming technology suitable for making sound superalloy preforms. The results indicated that high density (>99%) preforms (billets and rings) with little gas pick-ups and with the microstructural features of rapidly solidified superalloys, i.e. refined equiaxed grains and uniform microstructure, could be achieved after the optimisation of the spray atomisation and deposition process. The effects of subsequent thermal processing on the density, microstructure and mechanical properties of the spray formed superalloy were investigated. Compared to the turbine disks and rings made by wrought superalloys, the spray formed superalloys with identical chemistry showed significantly improved metallurgical quality, higher mechanical properties, and better hot workability.

scholarly journals Structure and Properties of Polysulfone Filled with Modified Twill Weave Carbon Fabrics

Polymers ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 50
Author(s):  
Dilyus I. Chukov ◽  
Sarvarkhodza G. Nematulloev ◽  
Viсtor V. Tсherdyntsev ◽  
Valerii G. Torokhov ◽  
Andrey A. Stepashkin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Surface Modification ◽  
Carbon Fibers ◽  
High Performance ◽  
Fiber Surface ◽  
Polymer Matrices ◽  
Thermosetting Polymers ◽  
Chemical Inertness ◽  
Twill Weave ◽  
Carbon Fabrics

Carbon fabrics are widely used in polymer based composites. Nowadays, most of the advanced high-performance composites are based on thermosetting polymer matrices such as epoxy resin. Thermoplastics have received high attention as polymer matrices due to their low curing duration, high chemical resistance, high recyclability, and mass production capability in comparison with thermosetting polymers. In this paper, we suggest thermoplastic based composite materials reinforced with carbon fibers. Composites based on polysulfone reinforced with carbon fabrics using polymer solvent impregnation were studied. It is well known that despite the excellent mechanical properties, carbon fibers possess poor wettability and adhesion to polymers because of the fiber surface chemical inertness and smoothness. Therefore, to improve the fiber–matrix interfacial interaction, the surface modification of the carbon fibers by thermal oxidation was used. It was shown that the surface modification resulted in a noticeable change in the functional composition of the carbon fibers’ surface and increased the mechanical properties of the polysulfone based composites. Significant increase in composites mechanical properties and thermal stability as a result of carbon fiber surface modification was observed.

Macroprobe Mode for the Study of Segregation in Steels

1990 ◽  
Vol 48 (2) ◽  
pp. 260-261
Author(s):  
Auclair Gilles ◽  
Benoit Danièle
Keyword(s):  
Mechanical Properties ◽  
Spatial Distribution ◽  
High Performance ◽  
Volume Fraction ◽  
Sheet Steel ◽  
Acquisition Time ◽  
Chemical Information ◽  
X Ray ◽  
Accurate Quantitative Analysis ◽  
Optical Micrographs

During these last 10 years, high performance correction procedures have been developed for classical EPMA, and it is nowadays possible to obtain accurate quantitative analysis even for soft X-ray radiations. It is also possible to perform EPMA by adapting this accurate quantitative procedures to unusual applications such as the measurement of the segregation on wide areas in as-cast and sheet steel products.The main objection for analysis of segregation in steel by means of a line-scan mode is that it requires a very heavy sampling plan to make sure that the most significant points are analyzed. Moreover only local chemical information is obtained whereas mechanical properties are also dependant on the volume fraction and the spatial distribution of highly segregated zones. For these reasons we have chosen to systematically acquire X-ray calibrated mappings which give pictures similar to optical micrographs. Although mapping requires lengthy acquisition time there is a corresponding increase in the information given by image anlysis.

Sign in / Sign up

Export Citation Format

Share Document