scholarly journals Sintering Behavior of CNT Reinforced Al6061 and Al2124 Nanocomposites

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Nouari Saheb
Keyword(s):  
Ball Milling ◽  
Sintering Behavior ◽  
Automotive Electronics ◽  
Composite Powders ◽  
Plasma Sintering ◽  
The Matrix ◽  
Potential Applications ◽  
Spark Plasma ◽  
Nanocomposite Powders ◽  
Very High

Ball milling and spark plasma sintering were successfully used to produce carbon nanotube reinforced Al6061 and Al2124 nanocomposites which have potential applications in the fields of aerospace, automotive, electronics, and high precision instrumentation. Al2124 and Al6061 nanocomposite powders containing 0.5 to 2 wt.% CNTs prepared through sonication and wet ball milling were spark plasma sintered at 400, 450, and 500°C for 20 minutes under a pressure of 35 MPa. CNTs were better dispersed, and less agglomerated and had good adhesion to the matrix in composites containing 1 wt.% CNTs. The increase of CNT content to 2 wt.% led to the formation of CNT clusters which resulted in less uniform and homogenous composite powders. Almost full densification of Al6061 reinforced with CNTs was achieved at 500°C. Also, CNTs reinforced Al2124 nanocomposites reached very high densities at 500°C. Composites reinforced with 1 wt.% CNTs displayed better densification compared to composites containing 2 wt.% CNTs. The increase of CNTs content from 0.5 to 1 wt.% increased the hardness of the Al6061 and Al2124 alloys to maximum values. Further increase of CNTs content to 2 wt.% decreased the hardness to values lower than that of the monolithic alloys.

Synthesis and Characterization of Cu–TiC Nanocomposites by Ball Milling and Spark Plasma Sintering

2014 ◽  
Vol 804 ◽  
pp. 173-176
Author(s):  
Nguyen Thi Hoang Oanh ◽  
Nguyen Hoang Viet ◽  
Jin Chun Kim ◽  
Ji Soon Kim
Keyword(s):  
Ball Milling ◽  
Spark Plasma Sintering ◽  
Milled Powder ◽  
X Ray Diffraction ◽  
Plasma Sintering ◽  
The Matrix ◽  
Spark Plasma ◽  
Diffraction Patterns ◽  
Nanocomposite Powders

In this study, Cu-TiC nanocomposites were fabricated from a mixture of Cu and 5÷15% wt. TiC powders by ball milling and subsequent spark-plasma sintering. The morphology of Cu-TiC nanocomposite powders were observed by field emission scanning electron microscopy. Only characteristic peaks of Cu and TiC phases were detected from X-ray diffraction patterns of milled powder mixture. Sintered compacts showed a highly densified compacts (∼95% relative density) while retaining fine grains in the matrix. The hardness, wear resistance, and fracture surface of the sintered specimens were also investigated.

scholarly journals Spark Plasma Sintering Behavior of Nb-Mo-Si Alloy Powders Fabricated by Hydrogenation-Dehydrogenation Method

Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3549 ◽  
Author(s):  
Sung Lee ◽  
Ki Park ◽  
Jang-Won Kang ◽  
Yanghoo Kim ◽  
Hyun-Su Kang ◽  
...  
Keyword(s):  
Spark Plasma Sintering ◽  
Sintering Temperature ◽  
Sintering Behavior ◽  
Powder Metallurgy Method ◽  
Composite Powders ◽  
Plasma Sintering ◽  
Formation Behavior ◽  
Spark Plasma ◽  
Two Phases ◽  
Nb5si3 Phase

In this study, the sintering behaviors of Nb-6Mo-20Si-3Cr (at percentage) in situ composite powders were studied. The Nb alloy powder was fabricated by a hydrogenation-dehydrogenation method, and both the alloy ingot and powders consisted of two phases: An Nb metal phase and the α-Nb5Si3 phase. Consolidation of the alloy powders was performed at 1500, 1600, and 1700 °C using spark plasma sintering, and the microstructures and phases formed at various sintering temperatures were analyzed. Micropores were observed in the compact sintered at 1500 °C due to the lack of complete densification at that temperature. The densification was completed at 1600 °C and the microstructure was slightly coarsened at 1700 °C compared to the microstructure of the compact sintered at 1600 °C. The microstructures prepared by the powder metallurgy method were finer than the microstructure of the ingot prepared by the casting method. The phase formation behavior varied according to the sintering temperature. Specifically, the α-Nb5Si3 phase, which is a stable structure of the Nb5Si3 phase at a low temperature, was transformed to the β-Nb5Si3 phase (which is stable at a high temperature) with an increasing sintering temperature.

scholarly journals Fabrication Process and Thermoelectric Properties of CNT/Bi2(Se,Te)3Composites

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Kyung Tae Kim ◽  
Yeong Seong Eom ◽  
Injoon Son
Keyword(s):  
Figure Of Merit ◽  
Reduction Process ◽  
Sintering Process ◽  
Composite Powders ◽  
Synergistic Enhancement ◽  
Dimensionless Figure Of Merit ◽  
Plasma Sintering ◽  
The Matrix ◽  
Spark Plasma ◽  
Matrix Modifications

Carbon nanotube/bismuth-selenium-tellurium composites were fabricated by consolidating CNT/Bi2(Se,Te)3composite powders prepared from a polyol-reduction process. The synthesized composite powders exhibit CNTs homogeneously dispersed among Bi2(Se,Te)3matrix nanopowders of 300 nm in size. The powders were densified into a CNT/Bi2(Se,Te)3composite in which CNTs were randomly dispersed in the matrix through spark plasma sintering process. The effect of an addition of Se on the dimensionless figure-of-merit (ZT) of the composite was clearly shown in 3 vol.% CNT/Bi2(Se,Te)3composite as compared to CNT/Bi2Te3composite throughout the temperature range of 298 to 473 K. These results imply that matrix modifications such as an addition of Se as well as the incorporation of CNTs into bismuth telluride thermoelectric materials is a promising means of achieving synergistic enhancement of the thermoelectric performance levels of these materials.

Synthesis and Characterization of Al-Alloy/SiCp Nanocomposites Employing High Energy Ball Milling and Spark Plasma Sintering

2011 ◽  
Vol 410 ◽  
pp. 224-227 ◽  
Author(s):  
Sivaiah Bathula ◽  
R.C. Anandani ◽  
Ajay Dhar ◽  
A.K. Srivastava
Keyword(s):  
Electron Microscopy ◽  
Ball Milling ◽  
High Energy ◽  
Synthesis And Characterization ◽  
Al Alloy ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Energy Ball ◽  
Nanocomposite Powders

This study reports the synthesis and characterization of Al-alloy/SiCpmetal matrix nanocomposite, synthesized using high energy ball milling followed by sintering employing spark plasma sintering (SPS). In the present investigation, Al 5083 alloy powder (15 μm) and 10wt.% SiC particulates (~20 nm) were milled in a high-energy planetary ball mill to produce nanocrystalline Al-alloy/SiC nanocomposite powders. X-ray diffraction analysis (XRD) was carried out for milled and un-milled powder and it was observed that, as the time of milling increased, the crystallite size of Al-alloy matrix decreased sharply. The average crystallite size of Al-matrix from XRD analysis was observed to be ~ 25 nm after 15 h of ball milling. Ball milled nanocomposite powders were consolidated and sintered employing SPS at a temperature range of 500°C with a heating rate of 300°C/min and the total sintering cycle was completed in 8 min. The mechanical properties were found to substantially increase after sintering employing SPS. Morphology of as received (un-milled) powders, milled powders and sintered nanocomposites were investigated by scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HR-TEM). The mechanical property evaluation of the sintered nanocomposite was done by measuring nanoindentation, micro-hardness and compressive strength.

scholarly journals Fabrication and Enhanced Thermoelectric Properties of Alumina Nanoparticle-Dispersed Bi0.5Sb1.5Te3Matrix Composites

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Kyung Tae Kim ◽  
Gook Hyun Ha
Keyword(s):  
Milling Process ◽  
Alumina Nanoparticles ◽  
Sintering Process ◽  
Composite Powders ◽  
Alumina Nanoparticle ◽  
Plasma Sintering ◽  
The Matrix ◽  
High Resolution Tem ◽  
Spark Plasma ◽  
P Type

Alumina nanoparticle-dispersed bismuth-antimony-tellurium matrix (Al2O3/BST) composite powders were fabricated by using ball milling process of alumina nanoparticle about 10 nm and p-type bismuth telluride nanopowders prepared from the mechanochemical process (MCP). The fabricated Al2O3/BST composite powders were a few hundreds of nanometer in size, with a clear Bi0.5Sb1.5Te3phase. The composite powders were consolidated into p-type bulk composite by spark plasma sintering process. High-resolution TEM images reveal that alumina nanoparticles were dispersed among the grain boundary or in the matrix grain. The sintered 0.3 vol.% Al2O3/BST composite exhibited significantly improved power factor and reduced thermal conductivity in the temperature ranging from 293 to 473 K compared to those of pure BST. From these results, the highly increased ZT value of 1.5 was obtained from 0.3 vol.% Al2O3/BST composite at 323 K.

scholarly journals Synergistic Strengthening Effect of Reinforcing Spark Plasma Sintered Al-Zn-TiC Nanocomposites with TiC Nanoparticles

Crystals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 842
Author(s):  
Hany S. Abdo ◽  
Asiful H. Seikh ◽  
Ahmed Fouly ◽  
Sameh A. Ragab
Keyword(s):  
Grain Size ◽  
Sem Analysis ◽  
Strengthening Effect ◽  
Plasma Sintering ◽  
Load Carrying ◽  
The Matrix ◽  
Microscopic Studies ◽  
Spark Plasma ◽  
Tic Nanoparticles ◽  
Nanocomposite Powders

In this investigation, Al-10Zn-TiC nanocomposite powders were prepared by varying the reinforcement content in wt.% via mechanical alloying in order to fabricate bulk samples via spark plasma sintering technique. The grain size exhibited in bulk samples was 17 ± 08 μm in 10 wt% TiC reinforced nanocomposites. The introduced TiC nanoparticles were improved the load carrying ability of the final product. The advanced microscopic studies such as X-ray diffraction analysis, SEM, HR-TEM along with the ring pattern were analysed to ensure the phases and their distribution of reinforced nanoparticles in the Al matrix. The XRD results revealed the formation of TiC present in the matrix, and SEM analysis conveys the uniform distribution and absence of clustering among the reinforcement particles; TEM results depicted the clear interface between the matrix and TiC nanoparticles. The mechanical properties such as hardness and compression studies were carried out in the bulk specimens. The obtained results confirmed the nanocomposites exhibit higher strength which was not only due to decrease in grain size but also due to the occurrence of different strengthening mechanisms such as grain boundary, Orowan and thermal expansion coefficient mismatch strengthening commensurate with the nanoscale TiC addition.

Thermal Stability and Properties of Cu-TiB2 Nanocomposites Prepared by Combustion Synthesis and Spark-Plasma Sintering

2007 ◽  
Vol 534-536 ◽  
pp. 1517-1520
Author(s):  
Dae Hwan Kwon ◽  
Thuy Dang Nguyen ◽  
Dina V. Dudina ◽  
Jong Won Kum ◽  
Pyuck Pa Choi ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Ball Milling ◽  
Copper Matrix ◽  
High Energy ◽  
Good Thermal Stability ◽  
Plasma Sintering ◽  
High Temperature Synthesis ◽  
Spark Plasma ◽  
Nanocomposite Powders ◽  
Tib2 Particles

In the present work, Cu-TiB2 nanocomposite powders were synthesized by combining high-energy ball-milling of Cu-Ti-B mixtures and subsequent self-propagating high temperature synthesis (SHS). Cu-40wt.%TiB2 powders were produced by SHS reaction and ball-milled. The milled SHS powder was mixed with Cu powders by ball milling to produce Cu-2.5wt.%TiB2 composites. TiB2 particles less than 250nm were formed in the copper matrix after SHS-reaction. The releative density, electrical conductivity and hardness of specimens sintered at 650-750°C were nearly 98%, 83%IACS and 71HRB, respectively. After heat treatment at 850 to 950°C for 2 hours under Ar atmosphere, hardness was descedned by 15%. Our Cu-TiB2 composite showed good thermal stability at eleveated temperature.

Febrication of MWNTs Composites with In Situ Precipitation Method

2007 ◽  
Vol 121-123 ◽  
pp. 135-138 ◽  
Author(s):  
Jing Wang ◽  
Hua Min Kou ◽  
Yu Bai Pan ◽  
Jing Kun Guo
Keyword(s):  
Aqueous Suspension ◽  
Precipitation Method ◽  
Composite Powders ◽  
Plasma Sintering ◽  
The Matrix ◽  
Ceramics Matrix ◽  
Multi Walled Carbon Nanotubes ◽  
Spark Plasma ◽  
Walled Carbon Nanotubes

In this article stable multi-walled carbon nanotubes (MWNTs) aqueous suspension with a 1.0 wt.% concentration was obtained with a very small quantity of dispersant. Precursor of ceramics were synthesized in the suspension and densely deposited on the surface of MWNTs successfully by a simple and effective in-situ precipitation method. The most important advantage for the in-situ composite method is to make MWNTs homogeneously distributed in the matrix. The fully dense compacts were obtained by spark-plasma-sintering (SPS) the in-situ precipitated composite powders at temperature 200 oC lower than that of composite powders made from the traditional mixing method. Furthermore, the microstructure and the mechanical property of the composites are much better than that of traditional method. The in-situ precipitation could be a promising method to fabricate CNTs composites of ceramics matrix especially those hard to sinter.

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