Effect of Thermal-Oxidative Aging on the Mechanical Properties of Carbon Fiber Reinforced Bis-Maleimide Composites

2010 ◽  
Vol 152-153 ◽  
pp. 829-833 ◽  
Author(s):  
Xin Ying Lv ◽  
Rong Guo Wang ◽  
Wen Bo Liu ◽  
Long Jiang

Bis-maleimide (BMI) resins are widely applied in carbon fiber reinforced polymer composites in aerospace fields, for their excellent thermal and mechanical properties. The effects of thermo-oxidative aging on mechanical properties of carbon fiber reinforced BMI composites were investigated by SEM with the combination of flexural strength test and inter-laminar shear strength (ILSS) test. The results indicated that the thermal-oxidative aging had some effects on mechanical properties of carbon fiber/BMI composites; however the testing temperature or service temperature had much more effects than aging time. With aging time increased, the flexural strength at 150 oC and the ILSS at 25 oC slightly increased, while the ILSS at 150 oC decreased gradually. Both test results of mechanical properties and fracture models of damaged flexural specimens by SEM indicated that the matrix resin in the composites showed some viscoelastic behaviors that resulted in the remarkable dependence of mechanical properties of the composites on temperature. Therefore, the carbon fiber reinforced BMI composites had lower flexural strength and ILSS at 150 oC than that at 25 oC.

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.


Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4592
Author(s):  
Chen Xiong ◽  
Tianhao Lan ◽  
Qiangsheng Li ◽  
Haodao Li ◽  
Wujian Long

This study investigates the feasibility of collaborative use of recycled carbon fiber reinforced polymer (RCFRP) fibers and recycled aggregate (RA) in concrete, which is called RCFRP fiber reinforced RA concrete (RFRAC). The mechanical properties of the composite were studied through experimental investigation, considering different RCFRP fiber contents (0%, 0.5%, 1.0%, and 1.5% by volume) and different RA replacement rates (0%, 10%, 20%, and 30% by volume). Specifically, ten different mixes were designed to explore the flowability and compressive and flexural strengths of the proposed composite. Experimental results indicated that the addition of RCFRP fibers and RA had a relatively small influence on the compressive strength of concrete (less than 5%). Moreover, the addition of RA slightly decreased the flexural strength of concrete, while the addition of RCFRP fibers could significantly improve the flexural performance. For example, the flexural strength of RA concrete with 1.5% RCFRP fiber addition increased by 32.7%. Considering the good flexural properties of the composite and its potential in reducing waste CFRP and construction solid waste, the proposed RFRAC is promising for use in civil concrete structures with high flexural performance requirements.


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.


2010 ◽  
Vol 434-435 ◽  
pp. 54-56 ◽  
Author(s):  
Jing Yu Liu ◽  
Ke Jian ◽  
Zhao Hui Chen ◽  
Zhi Wei Fang ◽  
Xia Hui Peng

Three dimensional carbon fiber reinforced silicon oxycarbide (3D Cf/Si-O-C) composites with low cost silicon resin as precursors and 3D Cf as reinforcement. Effects of adding SiC powder (SiCP) on the microstructure, mechanical properties and anti-oxidation properties of 3D Cf/Si-O-C composites were investigated. The results showed that adding SiCP filler could reduce the porosity and improve the interface bonding, therefore the properties of composites increased. But when the SiCP content was excessive, it was difficult to dense the matrix of composites at the further cycles and pores existed in the matrix. As a result, the mechanical properties of the composites decreased. It was found that when fabricated with 18.2 weight percent SiCP the composites exhibited highest mechanical properties, and the flexural strength and fracture toughness reached 421.3MPa and 13.0 MPa•m1/2, respectively. And the anti-oxidation properties were improved with the increase of the SiCP content. When fabricated with 25.0 weight percent SiCP the composites exhibited best oxidation resistance properties, and the composites retained 89.5% of original flexural strength.


2012 ◽  
Vol 512-515 ◽  
pp. 798-803 ◽  
Author(s):  
Shu Qi Guo ◽  
Toshiyuki Nishimura ◽  
Yutaka Kagawa

PAN and Pitch short carbon fiber-reinforced SiC matrix composites were fabricated by using a melting infiltration technique. The microstructure of the composites was characterized by scanning electron microscopy. The flexural strength of the composites was measured at room and high temperatures. The thermal conducitivity of the composites were evaluated. Effects of fibers on mechanical properties and thermal conductivity were assessed. The experimental results showed that the silicification of fibers during siliconizing was prevented due to the presence of barrier layer on the surface of fiber. Also, flexural strength and thermal conductivity depended on fibers used and content of fibers.


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.


1993 ◽  
Vol 2 (1) ◽  
pp. 096369359300200 ◽  
Author(s):  
R Selzer ◽  
K Friedrich

This investigation deals with the effect of moisture on the mechanical properties of carbon fiber reinforced polymer composites. Relationships between fracture-features and corresponding mechanical data are evaluated. The more the mechanical properties depend on the matrix and the interface, the more these properties are influenced by moisture.


2016 ◽  
Vol 51 (9) ◽  
pp. 1253-1264
Author(s):  
Wei Fan ◽  
Jia-lu Li ◽  
Shun-hou Fan ◽  
Xu Liu ◽  
Run-jun Sun ◽  
...  

The mechanical properties of carbon fiber-reinforced plastics used in aerospace are vulnerable to degradation under thermo-oxidative aging conditions. However, it is hard to establish a mechanical property prediction model for carbon fiber-reinforced plastics from thermo-oxidative aging mechanism point of view since the thermo-oxidative aging degradation processes are very complex. A mathematical model was proposed based on the theory of stochastic processes for predicting mechanical property degradation of carbon fiber-reinforced plastics under thermo-oxidative aging conditions in the present work. However, the predicted values calculated by the “random process model” were not in good agreement with experimental data. And then a “modified random process model” (namely a wider random process model) was established through Box–Cox transformation for random process model. The verification of the evaluation model showed that the modified random process model can nicely describe the mechanical performance degradation of carbon fiber-reinforced plastics with the increasing of aging time under certain aging temperatures. As the modified random process model was established without limiting the reinforced structure of carbon fiber-reinforced plastics, the described method provides an opportunity to rapidly predict the mechanical properties and the lifetime of any carbon fiber-reinforced plastics by testing the mechanical properties of carbon fiber-reinforced plastics before and after aging for a short period of time.


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