scholarly journals Rheological and Mechanical Properties of Silica/Nitrile Butadiene Rubber Vulcanizates with Eco-Friendly Ionic Liquid

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2763
Author(s):  
Munir Hussain ◽  
Sohail Yasin ◽  
Hafeezullah Memon ◽  
Zhiyun Li ◽  
Xinpeng Fan ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Volume Fraction ◽  
High Strength ◽  
Crosslinking Density ◽  
Mechanical And Thermal Properties ◽  
Butadiene Rubber ◽  
Transmission Electron ◽  
The Matrix ◽  
Silica Dispersion ◽  
The Impact

In this paper we designed greener rubber nanocomposites exhibiting high crosslinking density, and excellent mechanical and thermal properties, with a potential application in technical fields including high-strength and heat-resistance products. Herein 1-ethyl-3-methylimidazolium acetate ([EMIM]OAc) ionic liquid was combined with silane coupling agent to formulate the nanocomposites. The impact of [EMIM]OAc on silica dispersion in a nitrile rubber (NBR) matrix was investigated by a transmission electron microscope and scanning electron microscopy. The combined use of the ionic liquid and silane in an NBR/silica system facilitates the homogeneous dispersion of the silica volume fraction (φ) from 0.041 to 0.177 and enhances crosslinking density of the matrix up to three-fold in comparison with neat NBR, and also it is beneficial for solving the risks of alcohol emission and ignition during the rubber manufacturing. The introduction of ionic liquid greatly improves the mechanical strength (9.7 MPa) with respect to neat NBR vulcanizate, especially at high temperatures e.g., 100 °C. Furthermore, it impacts on rheological behaviors of the nanocomposites and tends to reduce energy dissipation for the vulcanizates under large amplitude dynamic shear deformation.

Ti (CN) Precipitation in Ultra-High Strength Ti Micro-Alloyed Steels with 700MPa Yield Strength on TSCR Process

2013 ◽  
Vol 842 ◽  
pp. 61-69 ◽  
Author(s):  
Qi Lin Chen ◽  
Xin Ping Mao ◽  
Xin Jun Sun
Keyword(s):  
Yield Strength ◽  
Volume Fraction ◽  
High Strength ◽  
High Volume ◽  
Thermal Simulation ◽  
Cast Slab ◽  
Transmission Electron ◽  
The Matrix ◽  
Segregation Band ◽  
Physical And Chemical

Precipitates in ultra-high strength Ti micro-alloyed strips with 700MPa yield strength on TSCR process and in the thermal simulation experimental specimen are observed via Scanning Electronic Microscope (SEM) and Transmission Electron Microscope (TEM), the results show that: the precipitates in the Ti micro-alloyed cast slab thermal simulation experiment can be divided into three categories: 1) micron-sized liquation TiN, 2) 100-200nm sized TiC formed along original austenite grain boundaries or along the dendrite segregation band, 3) solid precipitated 50-100nm sized TiN. Deformation induced spherical TiC (about 10nm-30nm) homogeneously distributed in the matrix after the austenite deformation .After simulated coiling, dispersed TiC (about 5-15nm ) precipitated from ferrite are found in the specimen. TiN with hundreds of nanometers size are commonly found in Ti micro-alloyed strips in industrial production. Ti4C2S2and Ti (CN) are complex precipitated, Ti4C2S2size is less than 30nm; physical and chemical phase analysis shows that the nanosized TiC precipitates are characterized by high volume fraction and small dimensions.

Physical Simulation of Weldability of Weldox 1300 Steel

2013 ◽  
Vol 762 ◽  
pp. 551-555 ◽  
Author(s):  
Marek Stanislaw Węglowski ◽  
Marian Zeman ◽  
Miroslaw Lomozik
Keyword(s):  
Mechanical Properties ◽  
Impact Toughness ◽  
Physical Simulation ◽  
High Strength ◽  
Parent Material ◽  
Cooling Time ◽  
Electron Microscopies ◽  
Transmission Electron ◽  
Transformation Diagrams ◽  
The Impact

In the present study, the investigation of weldability of new ultra-high strength - Weldox 1300 steel has been presented. The thermal simulated samples were used to investigate the effect of welding cooling time t8/5 on the microstructure and mechanical properties of the heat affected zone (HAZ). In the frame of these investigation the microstructure was studied by the light (LM) and transmission electron microscopies (TEM). It has been shown that the microstructure of the Weldox 1300 steel is composed of tempered martensite, and inside the laths the minor precipitations mainly V(CN) and molybdenum carbide Mo2C were observed. Mechanical properties of parent material were analysed by the tensile, impact and hardness tests. In details the influence of cooling time in the range of 2,5 - 300 s. on hardness, impact toughness and microstructure of simulated HAZ was studied by using welding thermal simulation test. The results show that the impact toughness and hardness decrease with the increase of t8/5 under the condition of a single thermal cycle in simulated HAZ. The continuous cooling transformation diagrams (CCT-W for welding conditions) of Weldox 1300 steel for welding purposes was also elaborated. The steel Weldox 1300 for cooling time in the range of 2,5 - 4 s showed martensite microstructure, for time from 4 s to 60 s mixture of martensite and bainite, and for longer cooling time mixture of ferrite, bainite and martensite. The results indicated that the weldability of Weldox 1300 steel is limited and to avoid the cold cracking the preheating procedure or medium net linear heat input should be used.

Design of High-Strength, High-Conductivity Alloys

MRS Bulletin ◽  
1996 ◽  
Vol 21 (6) ◽  
pp. 13-18 ◽  
Author(s):  
J. Miyake ◽  
G. Ghosh ◽  
M.E. Fine
Keyword(s):  
Electrical Conductivity ◽  
Computer Aided Design ◽  
Volume Fraction ◽  
High Strength ◽  
Pure Metal ◽  
Alloy Design ◽  
High Conductivity ◽  
Solid Solution Strengthening ◽  
Computer Aided ◽  
The Matrix

Computer-aided design of alloys is becoming increasingly useful, replacing the completely experimental approach. The computer-aided approach significantly reduces the cost of alloy design and more easily leads to optimum properties by reducing the amount of experimentation. Design of high-strength, high-conductivity alloys is a good example of the efficacy of using the computer to design experimental alloys.Alloys that have both high strength and high electrical conductivity are needed for many applications such as lead frames, connectors, conducting springs, and sliding contacts. Figure 1 shows the strength and conductivity of some commercially available copper-based alloys. Since dissolved solutes in an otherwise pure metal rapidly reduce the electrical conductivity (as well as the thermal conductivity), solid solution strengthening is not suitable for designing this class of alloys. Such alloys must be designed on the basis of precipitation or dispersion hardening. The theory of the yield stress of alloys with precipitates or dispersed phases has been well-formulated and may be used for alloy design. The solubility of the hardening phase in the matrix must be very small. Otherwise the conductivity will be degraded too much. Nordheim's rule relates conductivity to dissolved solute in alloys and is also available for alloy design. Decreasing the dissolved solute increases the conductivity and strength due to an increase in the volume fraction of the precipitate.

Mechanical Properties of Densified Untwisted Carbon Nanotube Yarn / Epoxy Composites

2015 ◽  
Author(s):  
Risa Yoshizaki ◽  
Kim Tae Sung ◽  
Atsushi Hosoi ◽  
Hiroyuki Kawada
Keyword(s):  
Mechanical Properties ◽  
Volume Fraction ◽  
Polymer Matrix Composites ◽  
High Strength ◽  
Matrix Composites ◽  
Specific Strength ◽  
The Matrix ◽  
Cnt Arrays ◽  
Strength And Stiffness ◽  
Long Fibers

Carbon nanotubes (CNTs) have very high specific strength and stiffness. The excellent properties make it possible to enhance the mechanical properties of polymer matrix composites. However, it is difficult to use CNTs as the reinforcement of long fibers because of the limitation of CNT growth. In recent years, a method to spin yarns from CNT forests has developed. We have succeeded in manufacturing the unidirectional composites reinforced with the densified untwisted CNT yarns. The untwisted CNT yarns have been manufactured by drawing CNTs through a die from vertically aligned CNT arrays. In this study, the densified untwisted CNT yarns with a polymer treatment were fabricated. The tensile strength and the elastic modulus of the yarns were improved significantly by the treatment, and they were 1.9 GPa and 140 GPa, respectively. Moreover, the polymer treatment prevented the CNT yarns from swelling due to impregnation of the matrix resin. Finally, the high strength CNT yarn composites which have higher volume fraction than a conventional method were successfully fabricated.

scholarly journals Enhancement of Mechanical and Thermal Properties of Polylactic Acid/Polycaprolactone Blends by Hydrophilic Nanoclay

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Chern Chiet Eng ◽  
Nor Azowa Ibrahim ◽  
Norhazlin Zainuddin ◽  
Hidayah Ariffin ◽  
Wan Md. Zin Wan Yunus ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Polylactic Acid ◽  
Mechanical Analysis ◽  
Basal Spacing ◽  
Mechanical And Thermal Properties ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
The Matrix ◽  
Thermal Stability Of

The effects of hydrophilic nanoclay, Nanomer PGV, on mechanical properties of Polylactic Acid (PLA)/Polycaprolactone (PCL) blends were investigated and compared with hydrophobic clay, Montmorillonite K10. The PLA/PCL/clay composites were prepared by melt intercalation technique and the composites were characterized by X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA), Dynamic Mechanical Analysis (DMA), Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM). FTIR spectra indicated that formation of hydrogen bond between hydrophilic clay with the matrix. XRD results show that shifting of basal spacing when clay incorporated into polymer matrix. TEM micrographs reveal the formation of agglomerate in the composites. Based on mechanical properties results, addition of clay Nanomer PGV significantly enhances the flexibility of PLA/PCL blends about 136.26%. TGA showed that the presence of clay improve thermal stability of blends. DMA show the addition of clay increase storage modulus and the presence of clay Nanomer PGV slightly shift two Tg of blends become closer suggest that the presence of clay slightly compatibilizer the PLA/PCL blends. SEM micrographs revealed that presence of Nanomer PGV in blends influence the miscibility of the blends. The PLA/PCL blends become more homogeneous and consist of single phase morphology.

Microstructure and Mechanical Properties of Twinning M/A Islands in a X100 High Strength Pipeline Steel

2017 ◽  
Vol 896 ◽  
pp. 182-189 ◽  
Author(s):  
Ji Ming Zhang ◽  
Qiang Chi ◽  
Ling Kang Ji ◽  
Hui Feng ◽  
Yan Hua Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Electron Microscope ◽  
Volume Fraction ◽  
Pipeline Steel ◽  
High Strength ◽  
Pipeline Steels ◽  
Transmission Electron ◽  
Fine Microstructure ◽  
X100 Pipeline Steel ◽  
Deformation Hardening

Fine microstructure of twinning Martensite/austenite (M/A) islands in a X100 high strength pipeline steel were analyzed by the scanning electron microscope (SEM) and high-resolution transmission electron microscope (HRTEM), and a uniaxial compressive experiment of micro-pillar for a twinning M/A island was conducted in present paper. The experimental results showed that M/A islands in X100 pipeline steels were consisted of retained austenite and nanoscale twins with sizes of less than ten nanometers. There were a few small blocks of nanoscale twins in an M/A island. Volume fraction of twinning M/A islands had an important effect on mechanical properties of X100 pipeline steels, with the increase of twinning M/A islands fraction, yield strength of X100 pipeline steel increased, and impact toughness of X100 pipeline steel decreased. The micro-pillar compression showed that the nanoscale twinning M/A island exhibited the higher deformation hardening during the compressive test, and its uniaxial compressive strength could up to 1.35GPa ultrahigh stress level.

A Methodology for Synthesizing High-Performance Robots Fabricated With Optimally Tailored Composite Laminates

1987 ◽  
Vol 109 (1) ◽  
pp. 74-86 ◽  
Author(s):  
C. K. Sung ◽  
B. S. Thompson
Keyword(s):  
Composite Laminates ◽  
High Performance ◽  
Volume Fraction ◽  
Three Dimensional ◽  
High Strength ◽  
Fiber Volume ◽  
Cross Sectional ◽  
Fiber Properties ◽  
Robot Arms ◽  
The Matrix

An essential ingredient of the next generation of robotic manipulators will be high-strength lightweight arms which promise high-performance characteristics. Currently, a design methodology for optimally synthesizing these essential robotic components does not exist. Herein, an approach is developed for addressing this void in the technology-base by integrating state-of-the-art techniques in both the science of composite materials and also the science of flexible robotic systems. This approach is based on the proposition that optimal performance can be achieved by fabricating robot arms with optimal cross-sectional geometries fabricated with optimally tailored composite laminates. A methodology is developed herein which synthesizes the manufacturing specification for laminates which are specifically tailored for robotic applications in which both high-strength, high-stiffness robot arms are required which also possess high material damping. The parameters in the manufacturing specification include the fiber-volume fraction, the matrix properties, the fiber properties, the ply layups, the stacking sequence and the ply thicknesses. This capability is then integrated within a finite-element methodology for analyzing the dynamic response of flexible robots. An illustrative example demonstrates the approach by simulating the three-dimensional elastodynamic response of a robot subjected to a prescribed spatial maneuver.

scholarly journals Development of SBR-Nanoclay Composites with Epoxidized Natural Rubber as Compatibilizer

2009 ◽  
Vol 2009 ◽  
pp. 1-5 ◽  
Author(s):  
R. Rajasekar ◽  
Gert Heinrich ◽  
Amit Das ◽  
Chapal Kumar Das
Keyword(s):  
Natural Rubber ◽  
Epoxidized Natural Rubber ◽  
Rubber Matrix ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Damping Characteristics ◽  
Transmission Electron ◽  
Organically Modified ◽  
The Matrix ◽  
Styrene Butadiene

The significant factor that determines the improvement of properties in rubber by the incorporation of nanoclay is its distribution in the rubber matrix. The simple mixing of nonpolar rubber and organically modified nanoclay will not contribute for the good dispersion of nanofiller in the rubbery matrix. Hence a polar rubber like epoxidized natural rubber (ENR) can be used as a compatibilizer in order to obtain a better dispersion of the nanoclay in the matrix polymer. Epoxidized natural rubber and organically modified nanoclay composites (EC) were prepared by solution mixing. The nanoclay employed in this study is Cloisite 20A. The obtained nanocomposites were incorporated in styrene butadiene-rubber (SBR) compounds with sulphur as a curing agent. The morphology observed through X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HR-TEM) shows that the nanoclay is highly intercalated in ENR, and further incorporation of EC in SBR matrix leads to partial exfoliation of the nanoclay. Dynamic mechanical thermal analysis showed an increase in storage modulus and lesser damping characteristics for the compounds containing EC loading in SBR matrix. In addition, these compounds showed improvement in the mechanical properties.

Effect of Two-Phase Region Quenching Temperature on Microstructure Evolution and Microhardness of HSLA100 Steel

2012 ◽  
Vol 602-604 ◽  
pp. 380-384
Author(s):  
X. Yan ◽  
G.F. Zhou ◽  
C.M. Zhu ◽  
J.S. Guan
Keyword(s):  
Microstructure Evolution ◽  
Volume Fraction ◽  
High Strength ◽  
Phase Region ◽  
Two Phase ◽  
Quenching Temperature ◽  
Island Structure ◽  
Transmission Electron ◽  
Evolution Characteristics ◽  
Lath Bainite

The microstructure evolution characteristics and those effects on microhardness of HSLA (high strength low alloy) 100 steel secondary quenched in the two-phase region were investigated. The results show that the mixed microstructure of ferrite and the M-A（mastenite-austenite）islands can be obtained in the intercritical quenching region. A small amount of island structure distributing along the lath ferrite quenched at 700°C is observed by transmission electron microscope (TEM). With the quenching temperature increasing, the island structure increases in quantity and coarsens in shape, at the same time, the ferrite gradually transform from single lath morphology to polygonal shape with the dislocation density lowing. When quenched at 820°C, the microstructure reverts to lath bainite. There is a good correlation between Vickers hardness value and the volume fraction of martensite or bainite HSLA100 steel quenched in the two-phase region. The microhardness value of the steel continually increase from 240HV to 320HV quenched at the range of 700°C to 820°C, and then keep a very small fluctuation around 320HV when the temperature exceeds to 820°C.

scholarly journals PHASE-TRANSFORMATION DYNAMICS AND CHARACTERIZATION OF PRECIPITATES IN THE Cu-3Ti-3Ni-0.5Si ALLOY

2021 ◽  
Vol 55 (4) ◽  
Author(s):  
Jia Liu ◽  
Jituo Liu ◽  
Xianhui Wang ◽  
Chong Fu ◽  
Yanlong Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Electrical Conductivity ◽  
Phase Transformation ◽  
Volume Fraction ◽  
Formation Enthalpy ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
The Matrix ◽  
Diffraction Patterns ◽  
Precipitated Phases

In this paper we investigated the phase-transformation dynamics of the Cu-3Ti-3Ni-0.5Si alloy by applying the Avrami method to phase-transformation dynamics and electrical conductivity based on the relationship between the electrical conductivity and the volume fraction of precipitates in the Cu-3Ti-3Ni-0.5Si alloy. The results corroborated well with the experimental data. The microstructure and precipitated phases were characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The analysis of the selected-area electron-diffraction patterns indicated that the precipitates formed in the matrix of the Cu-3Ti-3Ni-0.5Si alloy during aging, correspond to the Ni3Ti, Ni3Si, and Ni2Si phases. According to the values of formation enthalpy and cohesive energy determined by first-principle calculations, the formation of the Ni2Si phase is more favorable compared to the Ni3Si and Ni3Ti phases, and the Ni3Ti exhibits improved structural stability compared to the Ni2Si and Ni3Si phases.

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