Effects of SPS Parameters on the Mechanical Properties and Microstructures of Titanium Reinforced with Multi-Wall Carbon Nanotubes Produced by Hot Extrusion

2011 ◽  
pp. 821-828 ◽  
Author(s):  
Thotsaphon Threrujirapapong ◽  
Takahiro Mimoto ◽  
Katsuyoshi Kondoh ◽  
Junko Umeda ◽  
Bunshi Fugetsu
2011 ◽  
Vol 690 ◽  
pp. 339-342
Author(s):  
Katsuyoshi Kondoh ◽  
Thotsaphon Threrujirapapong ◽  
Hiroyuki Fukuda ◽  
Junko Umeda

By using light metal (Mg, Al, Ti) powders coated with un-bundled multi-wall carbon nanotubes (MWCNTs) via wet process, powder metallurgy (P/M) light metal matrix composite reinforced with un-bundled nanotubes was prepared by spark plasma sintering (SPS) and subsequently hot extrusion process. The microstructure and mechanical properties of the composites were evaluated. In the case of pure titanium, the distribution of CNTs and in-situ formed titanium carbide (TiC) compounds during sintering was investigated by optical and scanning electron microscopy (SEM) equipped with EDS analyzer. The mechanical properties of TMC were significantly improved by the additive of CNTs. For example, when employing the pure titanium composite powder coated with CNTs of 0.35 mass%, the increase of tensile strength and yield stress of the extruded TMC was 157 MPa and 169 MPa, respectively, compared to those of extruded titanium materials with no CNT additive. Fractured surfaces of tensile specimens were analyzed by SEM, and the uniform distribution of CNTs and TiC particles, being effective for the dispersion strengthening, at the surface of the TMC were obviously observed. In the case of Mg-Al alloys, in-situ formation of Al2MgC2compounds at the interface between CNTs and Mg-matrix occurred and effective for the tensile transfer loading, and resulted in the increment of tensile strength of the composite material.


Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4149
Author(s):  
Laura M. Echeverry-Cardona ◽  
Natalia Álzate ◽  
Elisabeth Restrepo-Parra ◽  
Rogelio Ospina ◽  
Jorge H. Quintero-Orozco

This study shows the energy optimization and stabilization in the time of solutions composed of H2O + TX-100 + Multi-Wall Carbon Nanotubes (MWCNTs), used to improve the mechanical properties of Portland cement pastes. For developing this research, sonication energies at 90, 190, 290, 340, 390, 440, 490 and 590 J/g are applied to a colloidal substance (MWCNTs/TX-100 + H2O) with a molarity of 10 mM. Raman spectroscopy analyses showed that, for energies greater than 440 J/g, there are ruptures and fragmentation of the MWCNTs; meanwhile at energies below 390 J/g, better dispersions are obtained. The stability of the dispersion over time was evaluated over 13 weeks using UV-vis spectroscopy and Zeta Potential. With the most relevant data collected, sonication energies of 190, 390 and 490 J/g, at 10 mM were selected at the first and the fourth week of storage to obtain Portland cement specimens. Finally, we found an improvement of the mechanical properties of the samples built with Portland cement and solutions stored for one and four weeks; it can be concluded that the MWCNTs improved the hydration period.


2008 ◽  
Vol 1143 ◽  
Author(s):  
Paola Ciselli ◽  
Lan Lu ◽  
James JC Busfield ◽  
Ton Peijs

ABSTRACTElastomeric composites based on Ethylene-Propylene-Diene-Monomer (EPDM) filled with multi-wall carbon nanotubes (MWNTs) have been prepared, showing improved mechanical properties as compared to the pure EPDM matrix. The results have been discussed using the Guth model. The main focus of the study was on the electrical behavior of the nanocomposites, in view of possible sensor applications. A linear relation has been found between conductivity and deformations up to 10% strain, which means that such materials could be used for applications such as strain or pressure sensors. Cyclic experiments were conducted to establish whether the linear relation was reversible, which is an important requirement for sensor materials.


2013 ◽  
Vol 652-654 ◽  
pp. 15-24 ◽  
Author(s):  
Xia Ran Miao ◽  
Yuan Jiang Qi ◽  
Xiao Yun Li ◽  
Yu Zhu Wang ◽  
Xiao Long Li ◽  
...  

The high density polyethylene (HDPE) nanocomposites were prepared by melt mixing HDPE with multi-wall carbon nanotubes (MWCNTs). In this work, the morphological, nucleation, crystallization and mechanical properties of the HDPE nanocomposites were studied by scanning electron microscopy, different scanning calorimetry, small-angle X-ray scattering and tensile testing. It was found that the tensile strength and Young’s modulus is increased by 42.4% and 116.5% at 3.wt% MWCNT loading compared to the pure HDPE. According to SEM results combined with SAXS, well-defined nanohybird shish-kebab (NHSK) entities exist in the composites, and in the shish-kebab structures fibrillous carbon nanotubes (MWCNTs) act as shish while HDPE lamellae act as kebab. The crystallization behavior, probed by DSC, suggests that MWCNTs have strong nucleation ability and shear stress plays an important role in polymer crystallization process. The mechanical properties demonstrated that the formation of the Shish-kebab structures improved the interfacial adhesion and brought obvious mechanical enhancement for the HDPE/MWCNTs nanocomposites.


Nanoscale ◽  
2017 ◽  
Vol 9 (31) ◽  
pp. 11017-11026 ◽  
Author(s):  
Ming Wang ◽  
Kai Zhang ◽  
Xin-Xin Dai ◽  
Yin Li ◽  
Jiang Guo ◽  
...  

Self-segregated PDMS/MWCNT nanocomposites exhibit high piezoresistive sensitivity, low percolation threshold and an enhanced mechanical properties.


e-Polymers ◽  
2009 ◽  
Vol 9 (1) ◽  
Author(s):  
Martino Colonna ◽  
Corrado Berti ◽  
Enrico Binassi ◽  
Maurizio Fiorini ◽  
Francesco Acquasanta ◽  
...  

AbstractMulti-wall carbon nanotubes/poly(butylene terephthalate) nanocomposites have been prepared by in-situ polymerization. Benzimidazolium tetrafluoroborate salts improve the dispersion of carbon nanotubes in the polymer matrix due to the formation of “π-cation” interactions of the imidazolium salt with the surface of the carbon nanotubes. An improved dispersion of the nanotubes in butanediol was also observed using the benzimidazolium salt. The presence of the compatibilization agent gives rise to improved thermo-mechanical properties and electrical conductivity for the nanocomposite. The presence of the nanotubes also consistently increases the thermal stability and enhances the nucleation process on PBT crystallization.


2013 ◽  
Vol 832 ◽  
pp. 338-343 ◽  
Author(s):  
Azira Abd. Aziz ◽  
A.I.H. Habibah Dayang ◽  
Abu Bakar Suriani ◽  
Mohamad Rusop Mahmood

Multi-walled carbon nanotubes (MWNTs) were used to prepare epoxidised natural rubber (ENR) nanocomposites. Our attempt to achieve nanostructures in MWNTs/ENR nanocomposites were formed by incorporating carbon nanotubes in a polymeric solution. Using this technique, nanotubes can be dispersed homogeneously in the ENR matrix with an attempt to increase the mechanical properties of these nanocomposites. The properties of the nanocomposites such as volume resistivity, tensile strength and tensile modulus were studied. Mechanical test results show an increase in the initial modulus for up to 14 times in relation to pure ENR. In addition to mechanical testing, the dispersion state of the MWNTs into ENR was studied by field emission electron microscopy (FESEM) and atomic force microscope (AFM) in order to understand the morphology of the resulting system. According to the present study, application of the physical and mechanical properties of carbon nanotubes to ENR can result in rubber products which have improved mechanical, physical and chemical properties.


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