Commercial purity aluminum was reinforced with different percentages of carbon nanohorns (CNH) using ball milling (1 h) followed by spark plasma sintering (SPS) at 550 °C for 5 min under 50 MPa pressure with heating rate 100 °C/min. The microstructure, hardness and compression properties of the spark-plasma-sintered carbon-nanohorns-reinforced aluminum (Al-CNH) composites were evaluated. Transmission electron microscopy revealed a uniform distribution of 0.3% CNH in Al, but above 0.3% CNH, agglomeration occurred. The compression strength of Al-0.3%CNH composites increased by 44% compared to the milled Al sample without CNH. © 2020, ASM International.

S. Sankaran

Department of Metallurgical and Materials Engineering

Haridoss Prathap

M. Jagannatham

Aluminum

Aluminum Compounds

Ball milling

carbon

Compressive strength

Electrons

High resolution transmission electron microscopy

Microscopic examination

microstructure

Milling (machining)

Reinforcement

Sintering

Spark plasma sintering

CARBON NANOHORN

COMMERCIAL PURITY ALUMINUM

COMPRESSION PROPERTIES

COMPRESSION STRENGTH

Microstructure and mechanical properties

REINFORCED ALUMINUM

REINFORCED ALUMINUM COMPOSITES

Uniform distribution

NANOHORNS

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Journal of Materials Engineering and Performance

Carbon nanotubes (CNT) are synthesized using arc discharge method in an open air. Various amounts of carbon nanotubes-reinforced AA7075 composites are prepared by powder metallurgy route and then hot extrusion at 450 °C. Hot-extruded composites are characterized, and mechanical properties are measured. Dry sliding wear properties of hot-extruded samples were evaluated using a pin-on-disk method for various loads (5-20 N) at room temperature and for various temperatures (100-400 °C) at the applied load 10 N as a function of CNT amount. Grain size of the composites is decreased compared with Al alloy matrix. Transmission electron microscopy of the composites revealed that the CNT are uniformly distributed in the composites. Mechanical properties of the hot-extruded composites are enhanced with an increase in CNT content. The wear performance is improved with an increased CNT amount, but decreases with an increase in the applied load and temperature as well. The wear damage is mild at lower applied loads and temperatures, whereas the damage is severe at 400 °C. The wear mechanism was plowing in the initial stages which is transformed to severe sliding and chipping with increasing load and temperature. The enhanced wear behavior of composites is attributed to self-lubricating nature of carbon nanotubes. © 2018, ASM International.

Mechanical and Tribological Behavior of Multiwalled Carbon Nanotubes-Reinforced AA7075 Composites Prepared by Powder Metallurgy and Hot Extrusion

In this study, Titania (TiO2) based composites reinforced with 2 wt% of various carbon nanomaterials were prepared using spark plasma sintering (SPS). Prior to SPS, the samples were ball milled. The reinforcements used in the composites were graphene nanoplatelets (GNP), carbon nanotubes (CNT) and single walled carbon nanohorns (SWNH). The ball milled powders and SPS compacts were characterized using various techniques. Mechanical and photocatalytic properties of the SPS composites were evaluated and compared for different nano-carbon reinforced TiO2 composites. X-ray diffraction and Raman spectroscopy studies confirmed that the milled powders comprised of Anatase phase which transformed into Rutile phase during SPS. Nano transformation twins were observed in Rutile grains. Fractured surfaces showed that the reinforcements were well bonded with the TiO2 grains and the SWNH reinforcement resulted in comparatively finer grain size. Nanoindentation studies showed that the hardness and elastic modulus of GNP reinforced composites was 78% and 30% respectively higher compared to TiO2 matrix. The hardness and modulus of the CNT reinforced TiO2 increased by 22% and 5.4% respectively while that of the SWNH reinforced TiO2 increased by 11% and 23% respectively. GNP and CNT reinforced TiO2 exhibited superior photocatalytic activity for the degradation of methylene blue dye compared to pure TiO2. © 2016 Elsevier Ltd and Techna Group S.r.l.

Ceramics International

Effect of different nano-carbon reinforcements on microstructure and properties of TiO2 composites prepared by spark plasma sintering

In this work, the rheological properties, thermal stability and the lap shear strength of epoxy adhesive joints reinforced with different carbon nano-fillers such as multi-walled carbon nanotubes (CNT), graphene nanoplatelets (GNP) and single-walled carbon nanohorns (CNH) have been studied. The nano-fillers were dispersed homogeneously using Brabender® Plasti-Corder®. The epoxy pre-polymer with and without the nano-fillers exhibited shear thinning behavior. The nano-filler epoxy mixtures exhibited a viscoplastic behavior which was analyzed using Casson's model. Thermo-gravimetric analysis indicated an increase in the thermal stability of the epoxy with the addition of carbon nano-fillers. Carbon nano-fillers resulted in increased lap shear strength having high Weibull modulus. The joint strength increased by 53%, 49% and 46% with the addition of 1 wt.% CNT, 0.5 wt.% GNP and 0.5 wt.% CNH, respectively. The strength of the joints having high filler content (>1 wt.%) was limited by mixed mode type of failure. © 2015 Elsevier Ltd. All rights reserved.

Composites Part A: Applied Science and Manufacturing

Effect of different carbon nano-fillers on rheological properties and lap shear strength of epoxy adhesive joints

Cost-effective synthesis of single walled carbon nanotube (SWCNT) and single walled carbon nanohorn (SWCNH) hybrids, in a single step, by electric arc discharge technique in open air, at lower current densities is reported. The rate of production of the hybrids is 3-5 g/h. The presence of SWCNTs and SWCNHs is confirmed by a transmission electron microscope (TEM). In addition to conventional larger Dahlia-like aggregates of nanohorns, unique nearly-spherical shaped and relatively smaller sized aggregates (mean size ∼ 25 nm) of nanohorns are formed along with thin bundles (mean diameter ∼ 5.7 nm) of SWCNTs. © 2015 Elsevier B.V. All rights reserved.

Diamond and Related Materials

Synthesis of thin bundled single walled carbon nanotubes and nanohorn hybrids by arc discharge technique in open air atmosphere

Electroless copper coatings were performed on purified carbon nanotubes (CNT), with varying deposition time and the optimum deposition time in terms of uniform deposition was determined to be 45. min. Different amounts of optimized Cu coated CNT (CNT (Cu)) and Al powders were ball milled. CNT (Cu) reinforced Al (Al-CNT (Cu)) composites were prepared by spark plasma sintering (SPS). Pure CNT reinforced Al (Al-CNT) composites were also prepared by SPS. The ball milled powders and composites were characterized using X-Ray diffraction, scanning electron microscopy, Raman spectroscopy, and transmission electron microscopy (TEM). Microhardness and compression properties of the composites were measured. TEM images of ball milled powders and composites revealed uniform distribution of CNT in matrix. Mechanical properties of Al-CNT (Cu) composites are superior to Al-CNT composites. The maximum enhancement in compressive strength of Al-CNT (Cu) composites is 154% for 2. wt% reinforcement; this enhancement is attributed to the copper coating on CNT surface. © 2015 Elsevier B.V.

Materials Science and Engineering A

Microstructure and mechanical behavior of copper coated multiwall carbon nanotubes reinforced aluminum composites

Microstructure and Mechanical Properties of Carbon Nanohorns Reinforced Aluminum Composites Prepared by Ball Milling and Spark Plasma Sintering

Journal	Data powered by TypesetJournal of Materials Engineering and Performance
Publisher	Data powered by TypesetSpringer
ISSN	10599495
Open Access	No