scholarly journals Effect of carbon nanotubes reinforcement on the mechanical properties of alumina and ZTA composites for ballistic application

Cerâmica ◽  
2018 ◽  
Vol 64 (372) ◽  
pp. 608-615 ◽  
Author(s):  
C. A. de O. Couto ◽  
S. Ribeiro ◽  
F. R. Passador
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Fracture Toughness ◽  
Sodium Dodecyl ◽  
Tetragonal Zirconia ◽  
Multiwall Carbon Nanotubes ◽  
Gum Arabic ◽  
Homogeneous Distribution ◽  
Acid Oxidation ◽  
Pure Alumina

Abstract Toughened and hardened alumina/carbon nanotubes and zirconia-toughened alumina (ZTA)/carbon nanotubes nanocomposites were developed by conventional ceramics route using pressureless sintering for the ballistic application. The multiwall carbon nanotubes (CNT) were functionalized with nitric acid oxidation reaction. Moreover, the surfactants sodium dodecyl sulphate and gum arabic were used to promote a homogeneous distribution of CNT in the ceramic matrix. Ceramic powders were prepared with pure alumina, alumina with the addition of 20 wt% of tetragonal zirconia/yttria, alumina/CNT and ZTA/CNT with the addition of 0.1 and 0.5 wt% of CNT. The morphology of nanocomposites was characterized by SEM-FEG. The mechanical properties of sintered samples were evaluated by flexural bending, Vickers microhardness and fracture toughness by SEVNB method. The addition of CNT in the ceramic and composite caused a general increase in densification, hardness, flexural strength and fracture toughness. ZTA composite with the addition of 0.1 wt% of CNT yielded the best results.

Effect of Sintering Schedule on the Microstructure of Carbon Nanotubes Reinforced Alumina Fabricated by SPS Method

2009 ◽  
Vol 66 ◽  
pp. 288-291
Author(s):  
Li Wei Huang ◽  
Zheng Yi Fu ◽  
Jin Yong Zhang ◽  
Wei Min Wang ◽  
Hao Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Fracture Toughness ◽  
Raman Spectrum ◽  
Sintering Temperature ◽  
Alumina Ceramics ◽  
Pure Alumina ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Sintering Method

Carbon nanotubes reinforced alumina was fabricated by spark plasma sintering method. When adding 0.2wt% nanotubes, the fracture toughness of the composites prepared increases 19% compared with the pure alumina ceramics. The effect of sintering schedule on microstructure and mechanical properties is investigated systematically. Microstructure studies reveal that at high sintering temperature, the nanotubes tend to gather in the gaps surrounded by three or more grains in a flocculent state, which leads to poor mechanical properties. Raman spectrum indicates that long sintering duration may cause serious nanotubes destruction and lower the mechanical properties.

scholarly journals Enhancing The Mechanical Properties of Chopped Basalt Composites by Incorporating of Multiwall Carbon Nanotubes

2019 ◽  
Vol 9 (1) ◽  
pp. 5646-5650
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Fracture Toughness ◽  
Mechanical Performance ◽  
Testing Machine ◽  
Basalt Fiber ◽  
Multiwall Carbon Nanotubes ◽  
Tensile Modulus ◽  
Basalt Fibre ◽  
Multiwall Carbon

This study aims to develop and determine mechanical properties chopped basalt fibre reinforced composites (CBFRP) modified with multiwall carbon nanotubes (CNT). Chopped basalt composite modified with CNT was fabricated using a combination of mechanical stirring and hand layup process. Three different weight percentages of CNT i.e. 0.5, 1, 1.5wt. % were filled into epoxy resin before mixing with chopped basalt fiber. The mechanical performance namely tensile properties and fracture toughness behaviour of the fabricated chopped basalt composites was assessed using Universal Testing Machine in accordance to ASTM standard D368 and D695, respectively. The results showed that the incorporation of CNT enhanced tensile and fracture toughness properties of the CBFRP composites. However, a higher amount of CNT (1.5wt%) incorporated into the CBFRP caused reduction in tensile strength, tensile modulus and Gic by 4.40%, 2.46% and 30.36 %, respectively, as compared to those of 1.0CNT-CBFRP

scholarly journals Effects of CNT Addition on Mechanical Properties, Electric Conductivity and Oxidation Resistance of Al2O3-TiC Composite

2013 ◽  
Vol 761 ◽  
pp. 83-86
Author(s):  
Hideaki Sano ◽  
Junichi Morisaki ◽  
Guo Bin Zheng ◽  
Yasuo Uchiyama
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Electric Conductivity ◽  
Young’S Modulus ◽  
Oxidation Resistance ◽  
Young's Modulus ◽  
Tic Particle

Effects of carbon nanotubes (CNT) addition on mechanical properties, electric conductivity and oxidation resistance of CNT/Al2O3-TiC composite were investigated. It was found that flexural strength, Young’s modulus and fracture toughness of the composites were improved by addition of more than 2 vol%-CNT. In the composites with more than 3 vol%-CNT, the oxidation resistance of the composite was degraded. In comparison with Al2O3-26vol%TiC sample as TiC particle-percolated sample, the Al2O3-12vol%TiC-3vol%CNT sample, which is not TiC particle-percolated sample, shows almost the same mechanical properties and electric conductivity, and also shows thinner oxidized region after oxidation at 1200°C due to less TiC in the composite.

scholarly journals Improving the mechanical properties of commercial feldspathic dental porcelain by addition of Alumina-Zirconia

2019 ◽  
pp. 67-76
Author(s):  
Juliana Gómez ◽  
Astrid Rueda ◽  
Edgar Alexader Ossa Henao
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Contact Resistance ◽  
Mechanical Performance ◽  
Tetragonal Zirconia ◽  
Dental Ceramics ◽  
Aesthetic Response ◽  
Early Failure ◽  
Feldspathic Porcelain ◽  
Natural Tooth

Dental ceramics made from Yttria stabilized tetragonal Zirconia polycrystalline (Y-TZP) with feldspathic porcelain veneers have similar mechanical and aesthetic response to natural tooth. However, cases of early failure, such as chipping or fracture in the veneering have been reported after short periods of use. The present study evaluated the feldspathic porcelain (VITA-VM9) with addition of 0.5 and 2.5 wt% Alumina-Zirconia as reinforcing agents. Hardness, fracture toughness, contact resistance and color variations were evaluated finding better mechanical performance on the new formulations.

Seawater effects on interlaminar fracture toughness of glass fiber/epoxy laminates modified with multiwall carbon nanotubes

2020 ◽  
pp. 002199832095078
Author(s):  
Julio A Rodríguez-González ◽  
Carlos Rubio-González
Keyword(s):  
Carbon Nanotubes ◽  
Fracture Toughness ◽  
Glass Fiber ◽  
Composite Laminates ◽  
Multiwall Carbon Nanotubes ◽  
Mode I ◽  
Mode Ii ◽  
Interlaminar Fracture Toughness ◽  
Multiscale Composite ◽  
Multiwall Carbon

In this work, the effect of seawater ageing on mode I and mode II interlaminar fracture toughness ([Formula: see text] and [Formula: see text]) of prepreg-based woven glass fiber/epoxy laminates with and without multiwall carbon nanotubes (MWCNTs) has been investigated. The first part of the investigation reports the moisture absorption behavior of multiscale composite laminates exposed to seawater ageing for ∼3912 h at 70 °C. Then, the results of mode I and mode II fracture tests are presented and a comparison of [Formula: see text] and [Formula: see text] for each type of material group and condition is made. Experimental results showed the significant effect of seawater ageing on [Formula: see text] of multiscale composite laminates due to matrix plasticization and fiber bridging. The improvement in [Formula: see text] of the wet glass fiber/epoxy laminate was about 50% higher than that of the neat laminate (without MWCNTs) under dry condition. It was also found that the presence of MWCNTs into composite laminates promotes a moderate increase (8%) in their [Formula: see text] as a result of the additional toughening mechanisms induced by CNTs during the delamination process. Scanning electron microscopy analysis conducted on fracture surface of specimens reveals the transition from brittle (smooth surface) to ductile (rough surface) in the morphology of composite laminates due to the influence of seawater ageing on the polymeric matrix and fiber/matrix interface.

scholarly journals Further Enhancement of Mechanical Properties of Conducting Rubber Composites Based on Multiwalled Carbon Nanotubes and Nitrile Rubber by Solvent Treatment

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1806 ◽  
Author(s):  
Pasi Keinänen ◽  
Amit Das ◽  
Jyrki Vuorinen
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Multiwall Carbon Nanotubes ◽  
Post Treatment ◽  
Nanocomposite Films ◽  
Butadiene Rubber ◽  
Rubber Composites ◽  
Multiwalled Carbon ◽  
Dispersion Agent ◽  
Dispersion Quality

Post-treatment removal of dispersion agents from carbon nanotube/rubber composites can greatly enhance the mechanical properties by increasing the filler–matrix interaction. In this study, multiwall carbon nanotubes (MWNT) were dispersed in water by sonication and nonionic surfactant, octyl-phenol-ethoxylate was used as a dispersion agent. The dispersed MWNTs were incorporated in thermo-reactive acrylonitrile butadiene rubber (NBR) latex and nanocomposite films were prepared by solution casting. As a post-treatment, the surfactant was removed with acetone and films were dried in air. Dispersion quality of the colloid before casting was determined, and mechanical, electrical and thermal properties of the composites before and after the acetone post-treatment were studied. It was found that removal of dispersion agent increased the storage modulus of films between 160–300% in all samples. Relative enhancement was greater in samples with better dispersion quality, whereas thermal conductivity changed more in samples with smaller dispersion quality values. Electrical properties were not notably affected.

scholarly journals Preparation and Mechanical Properties of Fe3Al-MWNTs Composites

2008 ◽  
Vol 17 (4) ◽  
pp. 096369350801700
Author(s):  
Laixue Pang ◽  
Jinsheng Zhang ◽  
Jing Xu
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Multiwall Carbon Nanotubes ◽  
High Yield ◽  
Matrix Composites ◽  
Intermetallic Matrix ◽  
First Results ◽  
Intermetallic Matrix Composites ◽  
Hot Pressing Sintering ◽  
Sintering Method

Multiwall carbon nanotubes (MWNT) reinforced iron aluminides (Fe3Al) intermetallic matrix composites have been prepared by a conventional (hot pressing) sintering method. Morphological, structural, compositional and mechanical properties investigations have been performed. Compressive testing shows that the composites still display high yield strength. The first results show that carbon nanotubes have been preserved in composite structure during the sintering process.

Effects of multiwall carbon nanotubes on dielectric and mechanical properties of CaCu3Ti4O12 composite

2020 ◽  
Vol 46 (12) ◽  
pp. 20313-20319
Author(s):  
Mohsen Ahmadipour ◽  
Mohammad Arjmand ◽  
Anh Thi Le ◽  
Sin Ling Chiam ◽  
Zainal Arifin Ahmad ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Multiwall Carbon Nanotubes ◽  
Dielectric And Mechanical Properties ◽  
Multiwall Carbon

Mechanical Properties of Zirconia/Alumina Nano-Composite after Soaking in Various Water-Based Conditions

2006 ◽  
Vol 309-311 ◽  
pp. 1219-1222 ◽  
Author(s):  
Seiji Ban ◽  
Masahiro Nawa ◽  
Y. Suehiro ◽  
H. Nakanishi
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Tetragonal Zirconia ◽  
Flexure Strength ◽  
Nano Composite ◽  
Dental Restorations ◽  
Dental Restoratives ◽  
All Ceramic ◽  
Water Based ◽  
Before And After

Yttria stabilized tetragonal zirconia polycrystals (Y-TZP) have been applied to dental crown and bridges. Whereas, to further improve its mechanical strength, the zirconia/alumina nano-composite stabilized with cerium oxide (Ce-TZP/Al2O3 nano-composite) was developed. In the present study, biaxial flexure strength, fracture toughness and hardness were determined before and after soaking in water-based conditions and the possibility of application to all ceramic dental restorations was discussed. In comparison to Y-TZP, Ce-TZP/Al2O3 nano-composite has quite high flexure strength and fracture toughness along with satisfied durability for LTAD in various water-based conditions encountered in dentistry. Therefore, it is concluded that the nano-composite can be safely applied to dental restoratives such as all-ceramic bridges.

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