Microstructures of Graphite/Copper Composites Prepared by Mechanical Milling and Hot Extrusion

To obtain graphite/copper composites with excellent microstructures, preparation process including mechanical milling, compact compressing, vacuum hot pressed sintering and hot extrusion had been put forward. Effect of milling time and hot extrusion on microstructures of composites had been analyzed and investigated by optical microscope. The results show that after mechanical milling, refined and uniform distributed graphite phase could optimize microstructures of composites. While increasing extrusion ratio, graphite particles and graphite fibers in longitudinal cross-section of composites could be refined effectively. Under of the same conditions, grain size of copper in graphite/copper composites is larger when raising extrusion temperature.

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Effect of Ball Milling on Mechanical Properties of Graphite/Copper Matrix Composites

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.217-218.936 ◽

2011 ◽

Vol 217-218 ◽

pp. 936-940 ◽

Cited By ~ 1

Author(s):

Yong Ping Jin ◽

Ming Hu

Keyword(s):

Ball Milling ◽

Testing Machine ◽

Hot Extrusion ◽

Hardness Test ◽

Copper Matrix ◽

Optical Microscope ◽

Matrix Composites ◽

Impact Machine ◽

Graphite Phase ◽

Copper Matrix Composites

3wt% graphite/copper matrix composites had been prepared after mechanical ball milling, pressing, vacuum hot pressed sintering and hot extrusion. With tensile test, hardness test and impact test, utilizing material testing machine, Vickers hardness tester, impact machine, optical microscope and scanning electron microscopy, effect of milling time on mechanical property of graphite/copper matrix composites had been investigated. The results show that after mechanical milling and hot extrusion, microstructure had been refined, distribution of graphite phase and cohesion between copper and graphite had been improved, mechanical locking force between copper matrix and graphite, tensile strength and hardness of composites had been increased. Elongation percentage and impact absorption work are less resulting from work-hardening during ball milling.

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Microstructure Evolution of Hot-Extruded Cu-15Ni-8Sn Alloy with Different Extrusion Ratios

Materials Science Forum ◽

10.4028/www.scientific.net/msf.898.1140 ◽

2017 ◽

Vol 898 ◽

pp. 1140-1147 ◽

Cited By ~ 1

Author(s):

Chao Zhao ◽

Xun Wang ◽

Yan Gen Yu ◽

Zong Qiang Luo ◽

Wei Wen Zhang

Keyword(s):

Heat Treatment ◽

Microstructure Evolution ◽

Cellular Structure ◽

Hot Extrusion ◽

Optical Microscope ◽

Extrusion Ratio ◽

Electron Backscattered Diffraction ◽

Hot Plastic Deformation ◽

Hardened Alloy ◽

Electronic Microscope

Cu-15Ni-8Sn alloy is a spinodal hardened alloy which possesses excellent combination of strength, elastic modulus, corrosion resistance and wear resistance. Much concern focuses on the microstructures and properties of this wrought alloys after heat treatment, however, the microstructure feature of the alloy during hot plastic deformation processing is rarely declared. The microstructure evolution of the hot-extruded Cu-15Ni-8Sn alloy with different extrusion ratio were investigated by optical microscope, scanning electronic microscope, electron backscattered diffraction. The results showed that dynamic recrystallization occured during hot extrusion at extrusion ratio ranging from 6 to 17. With the increase of extrusion ratio, the fraction of recrystallized grain increased. However, the amount of discontinuous γ precipitates reduced. The cellular structure was observed to grow not only on grain boundaries but also in the coarsening annealing grains when the extrusion ratio was below 13. When extrusion ratio was 17, the discontinuous γ precipitates and the residual annealing grains were suppressed and some recrystallized grains grew up.

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A TEM study of the effect of oxygen on nanocavity formation and precipitation in rapid - solidified Fe-16Ni-9Cr stainless steels

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100171237 ◽

1994 ◽

Vol 52 ◽

pp. 700-701

Author(s):

S. Wisutmethangoon ◽

T. F. Kelly ◽

J.E. Flinn

Keyword(s):

Stainless Steels ◽

High Mobility ◽

Hot Extrusion ◽

Extrusion Ratio ◽

Gas Atomization ◽

Cavity Formation ◽

Nucleation Sites ◽

Heat Treated ◽

Different Types ◽

Effect Of Oxygen

Vacancies are introduced into the crystal phase during quenching of rapid solidified materials. Cavity formation occurs because of the coalescence of the vacancies into a cluster. However, because of the high mobility of vacancies at high temperature, most of them will diffuse back into the liquid phase, and some will be lost to defects such as dislocations. Oxygen is known to stabilize cavities by decreasing the surface energy through a chemisorption process. These stabilized cavities, furthermore, act as effective nucleation sites for precipitates to form during aging. Four different types of powders with different oxygen contents were prepared by gas atomization processing. The atomized powders were then consolidated by hot extrusion at 900 °C with an extrusion ratio 10,5:1. After consolidation, specimens were heat treated at 1000 °C for 1 hr followed by water quenching. Finally, the specimens were aged at 600 °C for about 800 hrs. TEM samples were prepared from the gripends of tensile specimens of both unaged and aged alloys.

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Corrosion Behavior and Microstructural Evolution of Magnesium Powder with Milling Time Prepared by Mechanical Milling

Korean Journal of Metals and Materials ◽

10.3365/kjmm.2011.49.6.454 ◽

2016 ◽

Vol 49 (6) ◽

Keyword(s):

Corrosion Behavior ◽

Microstructural Evolution ◽

Mechanical Milling ◽

Milling Time ◽

Magnesium Powder

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A transverse and longitudinal cross-section separation in a π+ electroproduction coincidence experiment and the pion radius

Nuclear Physics B ◽

10.1016/0550-3213(77)90094-3 ◽

1977 ◽

Vol 120 (1) ◽

pp. 45-61 ◽

Cited By ~ 31

Author(s):

G. Bardin ◽

J. Duclos ◽

A. Magnon ◽

B. Mitchel ◽

J.C. Montret

Keyword(s):

Cross Section ◽

Longitudinal Cross Section ◽

Coincidence Experiment

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EVALUATION OF THE UPSTREAM WATER LEVEL OF THE FLOW OVER WEIRS WITH RECTANGULAR LONGITUDINAL CROSS-SECTION

Journal of Japan Society of Civil Engineers Ser B1 (Hydraulic Engineering) ◽

10.2208/jscejhe.77.1_54 ◽

2021 ◽

Vol 77 (1) ◽

pp. 54-58

Author(s):

Kesayoshi HADANO ◽

Kenji TATARA ◽

Hiroyuki NAGANO ◽

Kazumitsu MURAOKA

Keyword(s):

Water Level ◽

Cross Section ◽

Longitudinal Cross Section

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Effects of atmosphere and milling time on the coarsening of copper powders during mechanical milling

Powder Technology ◽

10.1016/j.powtec.2014.02.019 ◽

2014 ◽

Vol 256 ◽

pp. 251-256 ◽

Cited By ~ 31

Author(s):

Babu Madavali ◽

Jin-He Lee ◽

Jin Kyu Lee ◽

Kuk Young Cho ◽

Suryanarayana Challapalli ◽

...

Keyword(s):

Mechanical Milling ◽

Milling Time ◽

Copper Powders

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Preparation of Large Thin Area Vlsi Tem Specimens by Dimpling With A “Flatting Tool”

MRS Proceedings ◽

10.1557/proc-254-211 ◽

1991 ◽

Vol 254 ◽

Cited By ~ 1

Author(s):

Helen L. Humiston ◽

Bryan M. Tracy ◽

M. Lawrence ◽

A. Dass

Keyword(s):

Cross Section ◽

Milling Time ◽

Specimen Preparation ◽

Preparation Technique ◽

Ion Milling ◽

Sampling Area ◽

Preparation Methods

AbstractAn alternative VLSI TEM specimen preparation technique has been developed to produce 100μm diameter electron transparent thin area by using a conventional dimpler with a texmet padded ‘flatting tool’ for dimpling and a microcloth padded ‘flatting tool’ for polishing, followed by low angle ion milling. The advantages of this technique are a large sampling area and shorter milling times than conventional specimen preparation methods. In the following, we report the details of the modified dimpling technique. The improvements in available electron transparency, and a decrease in ion milling time are demonstrated with the preparation of planar and cross section VLSI device samples.

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Mechanical Milling and its Influence on Microstructure and Electric Conductivity of High Mass Fraction TiC / Cu Composites

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.815.790 ◽

2013 ◽

Vol 815 ◽

pp. 790-795

Author(s):

Jie Yan ◽

Kai Yong Jiang

Keyword(s):

Electrical Conductivity ◽

Relative Density ◽

Electric Conductivity ◽

Ball Milling ◽

Mechanical Milling ◽

Mass Fraction ◽

Milling Time ◽

High Mass ◽

Powder Metallurgy Method ◽

X Ray Diffraction

The TiC-Cu composites with different mass fraction were prepared by powder metallurgy method. The effect of ball milling time and sintering temperature on the morphology, relative density and electrical conductivity of TiC/Cu composites has been investigated. As-milled sintered compacts were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD) and conductivity measurements. The results demonstrate that under laboratory conditions with the milling time increasing grains are remarkable refined. Mechanical milling can bring about changes of lattice parameters, the grain size first decrease and then increase as milling time increasing. Relative density showed strong dependency on the milling time. The effect of the grain being refined by ball milling is helpless to improve electrical conductivity of composites. For the composites with TiC content<50wt.%, as milling time prolonging the electric conductivity decreases while for the 50%TiC-Cu the conductivity are not be impacted.

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