Cu-Al2O3 nanocomposite is successfully synthesized by reactive milling of CuO/Cu2O and Al. Wet milling in toluene transforms the combustion reaction to a progressive reaction. The extent of reduction reaction increases with increase in excess reductant (Al). The crystallite size of Cu obtained from reactive milling is much finer than that obtained from ball milling of Cu and Al2O3. © 2004 Elsevier B.V. All rights reserved.

Budaraju Srinivasa Murty

Department of Metallurgical and Materials Engineering

T. Venugopal

Alumina

Ball milling

combustion

Copper

reduction

Synthesis (chemical)

toluene

Crystallites

PROGRESSIVE REACTIONS

Reactive milling

WET MILLING

Nanostructured materials

industrial application

milling

Nanocomposite

Processing technique

synthesis

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

Materials Science and Engineering A

The B2-Aluminide matrix (FeAl and NiAl) with in-situ Al2O3 reinforcement were synthesized using reactive milling. The oxides (Fe2O3 and NiO) were reduced by Al during high energy milling to form Al2O3. The 20 h ball milled powders were consolidated using spark plasma sintering (SPS). To understand the densification mechanisms during SPS, sintering was performed at various temperatures (750–850 °C) and applied pressures (25–100 MPa). The creep parameters are evaluated from the densification data obtained during SPS using the model proposed by Bernard and Granger. In addition, independent constant-stress compression creep studies were conducted on the dense SPS pellets. The creep studies were performed on the composites at 800 °C at different stresses (100–500 MPa). The densification studies and compression creep studies are correlated based on the creep parameters obtained from both these studies and corroborated by TEM studies of the crept samples. This correlation is found to be valid even for the in-situ composites. Thus, the analysis of densification data can be helpful in predicting the creep behavior and useful for designing the new creep resistant alloys or composites. © 2017 Elsevier B.V.

Journal of Alloys and Compounds

Verification of correlation between densification during spark plasma sintering and compressive creep of ultrafine-grained in-situ Al2O3-reinforced B2 aluminide matrix composites

In the present study, Fe-10 vol pct Al2O3in situ nanocomposite has been derived by high-energy ball milling of Fe2O3-Fe-Al powder mixture followed by the consolidation using spark plasma sintering (SPS). The consolidated nanocomposite has bimodal-grained structure consisting of nanometer- and submicron-sized Fe grains along with nanometer-sized Al2O3, and Fe3O4 particles. The mechanical property analysis reveals that compressive yield strength of Fe-10 vol pct Al2O3 nanocomposite is 2100 MPa which is nearly two times higher than that of monolithic Fe processed by Mechanical Milling and SPS. The strengthening contributions obtained from matrix, grain size, and particles in the synthesized nanocomposite have been calculated theoretically, and are found to be matching well with the experimental strength levels. © 2016, The Minerals, Metals & Materials Society and ASM International.

Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science

Structure–Property Correlation in Fe-Al2O3 In Situ Nanocomposite Synthesized by High-Energy Ball Milling and Spark Plasma Sintering

The effect of mechanical activation on NiO-Al reaction has been investigated by carrying out high energy ball milling using toluene as the process controlling agent. NiO reduction reaction progresses gradually and a maximum of 70% reduction has been observed in 20 h of milling. Amorphous alumina forms as the product of NiO reduction and it transforms to stable α-Al2O3 at 1000 °C via the formation of metastable transition γ-Al2O3. The activation energy of NiO reduction in unmilled powder is 277 kJ/mol whereas in 20 h milled powder the activation energy has been reduced to 150 kJ/mol. © 2010 Elsevier B.V. All rights reserved.

Mechanical activation of aluminothermic reduction of NiO by high energy ball milling

NiAl-30 vol.% Al2O3 nanocomposite has been synthesized from the NiO-Al-Ni powder mixture by carrying out reactive milling in toluene medium and subsequent heating. The NiO reduction and the ordered NiAl phase formation occur simultaneously during milling. The unreacted NiO present in as milled powder is reduced by Al/NiAl at 420 °C on heating. Subsequent heating leads to the formation of a small amount of Ni3Al phase before it transforms completely to NiAl phase above 900 °C. Amorphous alumina is formed as the product of NiO reduction and it transforms to stable α-Al2O3 at 1000 °C via the formation of metastable transition γ-Al2O3. After heating to 1120 °C, the 20 h milled powder consists of nanocrystalline NiAl phase and α-Al2O3 with a crystallite size of 115 ± 40 nm size and 11 ± 3 nm, respectively. © 2009 Elsevier Ltd. All rights reserved.

Intermetallics

Synthesis of in-situ NiAl-Al2O3 nanocomposite by reactive milling and subsequent heat treatment

The Cu-W bulk nanocomposites of different compositions were successfully synthesized by high-energy ball milling of elemental powders. The nanocrystalline nature of the Cu-W composite powder is confirmed by X-ray diffraction analysis, transmission electron microscopy, and atomic force microscopy. The Cu-W nanocomposite powder could be sintered at 300-400 °C below the sintering temperature of the un-milled Cu-W powders. The Cu-W nanocomposites showed superior densification and hardness than that of un-milled Cu-W composites. The nanocomposites also have three times higher hardness to resistivity ratio in comparison to Oxygen free high conductivity copper. Copyright © 2007 American Scientific Publishers All rights reserved.

Journal of Nanoscience and Nanotechnology

Synthesis of Cu-W nanocomposite by high-energy ball milling

IOP Conference Series: Materials Science and Engineering

Cement Pavement Crack Identification Method Based on DFT Transformation and Crack Segment Splicing Method

Progress in Materials Science

Self-sustaining reactions induced by ball milling

Materials Science and Engineering: C

Characterization of Cu–Al2O3 nano-scale composites synthesized by in situ reduction

Scripta Materialia

Synthesis of Cu-Al 2 O 3 nano composite powder

Mechanical alloying and milling

Synthesis of copper-alumina nanocomposite by reactive milling

Journal	Materials Science and Engineering A
ISSN	09215093
Open Access	No