Effect of Nanosized Filler on Matrix Dominated Properties of Fiber Reinforced Epoxy

2011 ◽  
Author(s):  
Yuanxin Zhou ◽  
Shaik Jeelani
Keyword(s):  
Compression Strength ◽  
High Speed ◽  
High Vacuum ◽  
Trapped Air ◽  
Nano Fiber ◽  
Open Hole ◽  
Set Up ◽  
Mechanical Agitator ◽  
Laminar Shear ◽  
Nanosized Filler

In this study, a high-intensity ultrasonic liquid processor was used to obtain a homogeneous molecular mixture of epoxy resin and carbon nano fiber. The carbon nano fibers were infused into the part A of SC-15 (diglycidylether of Bisphenol A) through sonic cavitations and then mixed with part B of SC-15 (cycloaliphatic amine hardener) using a high-speed mechanical agitator. The trapped air and reaction volatiles were removed from the mixture using high vacuum. Nanophased epoxy with 2 wt.% CNF was then utilized in a vacuum assisted resin transfer molding (VARTM) set up with carbon fabric to fabricate laminated composites. The effectiveness of CNF addition on matrix dominated properties of composites has been evaluated by compression, open hole compression and inter-laminar shear. The compression strength, open hole compression strength and ILS were improved by 21%, 23% and 15%, respectively as compared to the neat composite.

Effect of Multiwalled Carbon Nanotube on Compression Properties of Carbon Fiber Reinforced Epoxy

2012 ◽  
Author(s):  
Yuanxin Zhou ◽  
Mahesh Hosur ◽  
Shaik Jeelani
Keyword(s):  
Epoxy Resin ◽  
Compression Strength ◽  
High Speed ◽  
High Vacuum ◽  
Compression Tests ◽  
Multiwalled Carbon ◽  
Compression Properties ◽  
Open Hole ◽  
Set Up ◽  
Mechanical Agitator

In this study, a high-intensity ultrasonic liquid processor was used to obtain a homogeneous mixture of epoxy resin and multi-walled carbon nanotubes (CNTs). The CNTs were infused into epon 862 epoxy resin through sonic cavitation and then mixed with W curing agent using a high-speed mechanical agitator. The trapped air and reaction volatiles were removed from the mixture using a high vacuum. Nanophased epoxy with 0.3 wt.% CNT was utilized in a vacuum assisted resin transfer molding (VARTM) set up with carbon fabric to fabricate laminated composites. The effectiveness of CNT addition on matrix dominated properties of composites has been evaluated by compression and open hole compression tests. The compression strength and open hole compression strength were improved by 31% and 39%, respectively, as compared to the neat composite.

Improvement in Mechanical Properties of Clay Filled Carbon-Epoxy Composite

2006 ◽  
Author(s):  
Yuanxin Zhou ◽  
Farhana Pervin ◽  
Jamese Hamilton ◽  
Shaik Jeelani
Keyword(s):  
Mechanical Properties ◽  
Epoxy Resin ◽  
High Speed ◽  
High Vacuum ◽  
Test Results ◽  
Trapped Air ◽  
Set Up ◽  
Flexural Tests ◽  
Mechanical Agitator ◽  
Mmt Clay

In the present investigation, a high intensity ultrasonic liquid processor was used to obtain a homogeneous molecular mixture of epoxy resin and K-10 MMT clay. The clay were infused into the part A of SC-15 (Diglycidylether of Bisphenol A) through sonic cavitations and then mixed with part B of SC-15 (cycloaliphatic amine hardener) using a high speed mechanical agitator. The trapped air and reaction volatiles were removed from the mixture using high vacuum. Flexural tests were performed on unfilled, 1wt. %, 2wt. %, 3 wt. % and 4 wt.% clay filled SC-15 epoxy to identify the loading effect on mechanical properties of the composites. The flexural test results indicate that 2.0 wt% loading of clay in epoxy resin showed the highest improvement in strength as compared to the neat systems. After that, the nanophased matrix with 2 wt.% clay is then utilized in a Vacuum Assisted Resin Transfer Molding (VARTM) set up with satin weave carbon preforms to fabricate laminated composites. The resulting structural composites have been tested under flexural and tensile loads to evaluate mechanical properties. 13.5% improvement in flexural strength and 5.8% improvement in tensile strength were observed in carbon/epoxy nanocomposite. TGA and DMA tests were also conducted to observe the thermal stability of the structural composite.

Evaluation of Thermal and Mechanical Properties of Carbon Nano Fiber Reinforced SC-15 Epoxy

Materials ◽  
2005 ◽  
Author(s):  
Farhana Pervin ◽  
Yuanxin Zhou ◽  
Vijay Rangaree ◽  
Shaikh Jelanee
Keyword(s):  
Mechanical Properties ◽  
Epoxy Resin ◽  
High Speed ◽  
Morphological Changes ◽  
High Vacuum ◽  
Thermal And Mechanical Properties ◽  
Entire Volume ◽  
Bending Tests ◽  
Nano Fiber ◽  
Mechanical Agitator

In the present investigation we have developed a novel technique to fabricate nanocomposite materials containing SC-15 epoxy resin and carbon nano fiber (CNF). A high intensity ultrasonic liquid processor was used to obtain a homogeneous molecular mixture of epoxy resin and carbon nano fiber. The carbon nano fibers were infused into the part A of SC-15 (Diglycidylether of Bisphenol A) through sonic cavitations and then mixed with part B of SC-15 (cycloaliphatic amine hardener) using a high speed mechanical agitator. The trapped air and reaction volatiles were removed from the reaction mixture using high vacuum. TGA, DMA and 3-point bending tests were performed on unfilled, 1wt. %, 2wt. % and 4wt. % CNF filled SC-15 epoxy to identify the loading effect on thermal and mechanical properties of the composites. The flexural results indicate that both modulus and strength increased with increasing loading percentage of CNF. DMA studies also revealed that filling the carbon nano fiber into epoxy can improve storage modulus and Tg compared to neat system. However, TGA results show that thermal stability of composite insensitive to the fiber content. The fracture surfaces, dispersions and morphological changes of composites were studied by scanning electron microscope (SEM). These results indicate that the carbon nano fiber is about 200nm in the diameter and 20–100um in the length and are nearly uniformly dispersed over the entire volume of the resin.

Effect of Carbon Nanotube on Electrical, Thermal and Mechanical Properties of Epoxy

2007 ◽  
Author(s):  
Yuanxin Zhou ◽  
Peixuan Wu ◽  
Zhongyang Cheng ◽  
Biddut Kanti Dey ◽  
Shaik Jeelani
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Carbon Nanotube ◽  
High Speed ◽  
Mechanical Test ◽  
High Vacuum ◽  
Mechanical Analysis ◽  
Thermal And Mechanical Properties ◽  
Multi Walled Carbon Nanotubes ◽  
Mechanical Agitator

In this study, electrical, thermal and mechanical properties of multi-walled carbon nanotubes (CNTs) reinforced Epon 862 epoxy have been evaluated. Firstly, 0.1 wt%, 0.2 wt%, 0.3 wt%, and 0.4 wt% CNT were infused into epoxy through a high intensity ultrasonic liquid processor and then mixed with EpiCure curing agent W using a high speed mechanical agitator. The trapped air and reaction volatiles were removed from the mixture using a high vacuum. Neat epoxy sample also was made as reference. Electrical conductivity, dynamic mechanical analysis (DMA, three point bending tests and fracture tests were performed on unfilled, CNT-filled epoxy to identify the loading effect on the properties of composites. Experimental results show significant improvement in electric conductivity. The resistivity of epoxy decreased to 15Ωm with 0.4% CNT. DMA studies revealed that filling the carbon nanotube into epoxy can produce a 90% enhancement in storage modulus and a 17° C increase in Tg, but CNT has little effect on decomposing temperature. Mechanical test results showed that modulus increased with higher CNT loading percentages, but the 0.3 wt% CNT-infusion system showed the maximum strength and fracture toughness enhancement. The decrease in strength and fracture toughness in 0.4% CNT/epoxy was attributed to poor dispersions of nanotubes in the composite.

Vacuum System to Minimize the Specimen Contamination of High-Performance EM

1977 ◽  
Vol 35 ◽  
pp. 68-69
Author(s):  
N. Yoshimura ◽  
K. Shirota ◽  
T. Etoh
Keyword(s):  
Electron Microscope ◽  
High Speed ◽  
High Performance ◽  
High Vacuum ◽  
Vacuum System ◽  
Pump System ◽  
Pumping System ◽  
Diffusion Pump ◽  
Almost All ◽  
Cascade Type

One of the most important requirements for a high-performance EM, especially an analytical EM using a fine beam probe, is to prevent specimen contamination by providing a clean high vacuum in the vicinity of the specimen. However, in almost all commercial EMs, the pressure in the vicinity of the specimen under observation is usually more than ten times higher than the pressure measured at the punping line. The EM column inevitably requires the use of greased Viton O-rings for fine movement, and specimens and films need to be exchanged frequently and several attachments may also be exchanged. For these reasons, a high speed pumping system, as well as a clean vacuum system, is now required. A newly developed electron microscope, the JEM-100CX features clean high vacuum in the vicinity of the specimen, realized by the use of a CASCADE type diffusion pump system which has been essentially improved over its predeces- sorD employed on the JEM-100C.

scholarly journals Research on Performance Test System of Space Harmonic Reducer in High Vacuum and Low Temperature Environment

Machines ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 1
Author(s):  
Jing Wang ◽  
Zhihua Wan ◽  
Zhurong Dong ◽  
Zhengguo Li
Keyword(s):  
Low Temperature ◽  
High Speed ◽  
Performance Test ◽  
High Reliability ◽  
High Vacuum ◽  
Test System ◽  
Low Noise ◽  
Speed Ratio ◽  
Space Harmonic ◽  
Temperature Environment

The harmonic reducer, with its advantages of high precision, low noise, light weight, and high speed ratio, has been widely used in aerospace solar wing deployment mechanisms, antenna pointing mechanisms, robot joints, and other precision transmission fields. Accurately predicting the performance of the harmonic reducer under various application conditions is of great significance to the high reliability and long life of the harmonic reducer. In this paper, a set of automatic harmonic reducer performance test systems is designed. By using the CANOpen bus interface to control the servo motor as the drive motor, through accurately controlling the motor speed and rotation angle, collecting the angle, torque, and current in real time, the life cycle test of space harmonic reducer was carried out in high vacuum and low temperature environment on the ground. Then, the collected data were automatically analyzed and calculated. The test data of the transmission accuracy, backlash, and transmission efficiency of the space harmonic reducer were obtained. It is proven by experiments that the performance data of the harmonic reducer in space work can be more accurately obtained by using the test system mentioned in this paper, which is convenient for further research on related lubricating materials.

scholarly journals A Selective Solar Absorber for Unconcentrated Solar Thermal Panels

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 900
Author(s):  
Davide De Maio ◽  
Carmine D’Alessandro ◽  
Antonio Caldarelli ◽  
Daniela De Luca ◽  
Emiliano Di Gennaro ◽  
...  
Keyword(s):  
Fossil Fuels ◽  
High Vacuum ◽  
Optimization Procedure ◽  
Energy Transition ◽  
Spectral Emissivity ◽  
Thermal Conversion ◽  
Stagnation Temperature ◽  
Solar Absorber ◽  
Analytical Formulas ◽  
Set Up

A new Selective Solar Absorber, designed to improve the Sun-to-thermal conversion efficiency at mid temperatures in high vacuum flat thermal collectors, is presented. Efficiency has been evaluated by using analytical formulas and a numerical thermal model. Both results have been experimentally validated using a commercial absorber in a custom experimental set-up. The optimization procedure aimed at obtaining Selective Solar Absorber is presented and discussed in the case of a metal dielectric multilayer based on Cr2O3 and Ti. The importance of adopting a real spectral emissivity curve to estimate high thermal efficiency at high temperatures in a selective solar absorber is outlined. Optimized absorber multilayers can be 10% more efficient than the commercial alternative at 250 °C operating temperatures, reaching 400 °C stagnation temperature without Sun concentration confirming that high vacuum flat thermal collectors can give important contribution to the energy transition from fossil fuels to renewable energy for efficient heat production.

Study on Magnetic Barrel Machine Equipped with Three-Dimensional Arrangement of Magnets

2007 ◽  
Vol 329 ◽  
pp. 761-766 ◽  
Author(s):  
Y. Zhang ◽  
Masato Yoshioka ◽  
Shin-Ichiro Hira
Keyword(s):  
High Speed ◽  
Permanent Magnets ◽  
Three Dimensional ◽  
Video Camera ◽  
High Speed Video ◽  
High Speed Video Camera ◽  
The Media ◽  
Set Up

At present, a commercially available magnetic barrel machine equipped with permanent magnets has some faults arising from constructional reason. That is, grinding or finishing ability is different from place to place in the machining region, resulting in the limitation on the region we can use in the container of workpieces. Therefore, in this research, authors made the new magnetic barrel machine equipped with three dimensional (3D) magnet arrangement to overcome these faults. The grinding ability of the new 3D magnetic barrel machine converted was experimentally examined, and compared with that of the traditional magnetic barrel machine. As a result, it was shown that we can use much broader region in the new 3D machine. It was also shown that the grinding ability became higher. The distribution of barrel media in action was recorded by means of a high speed video camera. It was clarified that the media rose up higher and were distributed more uniformly in the container by the effect of the magnet block newly set up. It was supposed that this must be the reason for the above-mentioned improvement of grinding ability.

scholarly journals Set-up of a high-resolution 300 mK atomic force microscope in an ultra-high vacuum compatible 3He/10 T cryostat

2016 ◽  
Vol 87 (7) ◽  
pp. 073702 ◽  
Author(s):  
H. von Allwörden ◽  
K. Ruschmeier ◽  
A. Köhler ◽  
T. Eelbo ◽  
A. Schwarz ◽  
...  
Keyword(s):  
High Resolution ◽  
Atomic Force Microscope ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Atomic Force ◽  
Set Up
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