Densification of Mechanically Alloyed Al5083-5wt% Y2O3 Nano Composite by Equal Channel Angular Pressing

2014 ◽  
Vol 592-594 ◽  
pp. 963-967
Author(s):  
Pravir Polly ◽  
K. Chandra Sekhar ◽  
Balasubramanian Ravisankar ◽  
S. Kumaran
Keyword(s):  
Equal Channel Angular Pressing ◽  
Single Phase ◽  
Milled Powder ◽  
High Energy ◽  
X Ray Diffraction ◽  
Mechanically Alloyed ◽  
Nano Composite ◽  
Angular Pressing ◽  
Energy Ball ◽  
Milled Powders

In the present work, Al-5083-5wt% nanoyttria powders were milled for 10, 20, 30 and 35 hrs in a high energy ball milling under optimised process parameters. The milled powders were characterised by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Milled powders exhibit nanocrystalline single phase after 10hrs of milling. Consolidation of 35 hrs milled powder was done by equal channel angular pressing (ECAP) through 90odie channel angle using route A upto three passes with and without back pressure and sintered under controlled environment. Density of ECAPed samples was measured using Archimedes principle. The density is 96% for the sample consolidated with backpressure after two passes after sintering.

Characterization of Mechanically Alloyed Al5083 Alloy and Composite and Consolidation by Equal Channel Angular Pressing

2015 ◽  
Vol 764-765 ◽  
pp. 23-27 ◽  
Author(s):  
G. Kondaiah ◽  
K. Chandra Sekhar ◽  
B. Chaithanyakrushna ◽  
Balasubramanian Ravisankar ◽  
S. Kumaran
Keyword(s):  
Equal Channel Angular Pressing ◽  
Back Pressure ◽  
X Ray Diffraction ◽  
Mechanically Alloyed ◽  
Composite Powders ◽  
Oxide Powders ◽  
Angular Pressing ◽  
Al 5083 Alloy ◽  
Milled Powders

In the present work a comparative study was carried out on consolidation of Al-5083 alloy and 5wt. % nanoyttrium oxide powders by Equal channel angular pressing (ECAP). The powders were milled for 10, 15 and 20 hrs using planetary ball mill under optimized process parameters. The milled powders were characterised by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Milled powders exhibit nanocrystalline single phase after 10hrs. The crystallite size after 20 hr of milling, alloy and composite powders were found to be 23nm and 57nm respectively. The 20hr milled alloy and composite powder was consolidated by equal channel angular pressing (ECAP) through 90o die channel angle using route-A for two passes with and without back pressure. Density of ECAPed samples were measured using Archimedes principle. The highest density was found as 96% for the alloy after 2 passes without backpressure and sintering and 94% for the composite after 2 passes with back pressure and sintering.

ROLE OF PROCESS CONTROL AGENT ON MECHANICAL ALLOYING OF NANO STRUCTURED TiAl-BASED ALLOY

2008 ◽  
Vol 22 (18n19) ◽  
pp. 2933-2938 ◽  
Author(s):  
H. BAHMANPOUR ◽  
S. HESHMATI-MANESH
Keyword(s):  
Process Control ◽  
Stearic Acid ◽  
Milled Powder ◽  
High Energy ◽  
Control Agent ◽  
X Ray Diffraction ◽  
Process Control Agent ◽  
Crystallite Sizes ◽  
Energy Ball ◽  
Milled Powders

High energy ball milling was performed on a mixture of titanium and aluminum elemental powders with a composition of Ti -48(at.%) Al . Stearic acid was added to this powder mixture as a process control agent (PCA) to study its effect on the microstructure evolution and crystallite size of the milled powder after various milling times. Phase compositions and morphology of the milled powders were evaluated using X-ray diffraction and scanning electron microscopy. Crystallite sizes of milled powders were determined by Cauchy-Gaussian approach using XRD profiles. It was shown that addition of 1wt.% of stearic acid not only minimizes the adhesion of milling product to the vial and balls, but also reduces its crystallite sizes. It has also a marked effect on the morphology of the final product.

The Transformation of Co-Rich Alloys Produced by Mechanical Alloying

2006 ◽  
Vol 509 ◽  
pp. 135-140
Author(s):  
Francisco Cruz-Gandarilla ◽  
R. Gayosso-Armenta ◽  
J. Gerardo Cabañas-Moreno ◽  
Heberto Balmori-Ramírez
Keyword(s):  
Single Phase ◽  
Intermetallic Phase ◽  
High Energy ◽  
Inert Atmosphere ◽  
X Ray Diffraction ◽  
Mechanically Alloyed ◽  
Powder Mixtures ◽  
X Ray ◽  
Heat Treated ◽  
Energy Ball

Elemental powder mixtures of Co and Ti were subjected to high-energy ball milling in order to produce mechanically alloyed powders with nominal compositions Co64Ti36, Co67Ti33, Co70Ti30, Co73Ti27, Co76Ti24 and Co85Ti15. The mechanically alloyed powders were treated during 30 minutes in inert atmosphere at temperatures in the range 300 – 700 °C. Both the as-milled powders as well as those subjected to heat treatments have been characterized by x-ray diffraction, scanning electron microscopy, energy-dispersive x-ray spectrometry and differential thermal analysis. As-milled products consist mostly of agglomerated powders with a size between 10 and 80 µm which give an amorphous-like diffraction pattern, except for the Co85Ti15 sample whose pattern presents the characteristic peaks of the Co3Ti intermetallic phase. The transformation of the asmilled powders occurs at temperatures in the range of about 530 – 670 °C with clearly observed exothermic events. The Co3Ti phase is found in all heat treated samples, together with fcc-Co (in Co76Ti24 and Co85Ti15) or the hexagonal Co2Ti intermetallic phase (in Co64Ti36, Co67Ti33 and Co70Ti30); the Co73Ti27 sample was essentially single-phase Co3Ti after heating to 700 °C. Our results suggest the occurrence of crystallization of an amorphous phase in two overlapping stages during heating of the mechanically alloyed powders.

Effect of Equal Channel Angular Pressing on Densification Behavior of Al 5083 Alloy Powder

2015 ◽  
Vol 830-831 ◽  
pp. 63-66 ◽  
Author(s):  
Kondaiah Gudimetla ◽  
Ganesh Varma Jampana ◽  
S. Ramesh Kumar ◽  
Balasubramanian Ravisankar ◽  
S. Kumaran
Keyword(s):  
Equal Channel Angular Pressing ◽  
Physical And Mechanical Properties ◽  
High Energy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Angular Pressing ◽  
Al 5083 Alloy ◽  
Energy Ball ◽  
Particle Size And Morphology ◽  
Size And Morphology

In this present study Al-5083 alloy powders were prepared from elemental powders using high energy ball milling under optimized milling parameters. Various properties such as crystalline size, particle size and morphology have been studied using X-Ray diffraction analysis and Scanning Electron Microscopy. It was found that Al-5083 alloy was formed and nanocrystalline size particles were achieved. These nanocrystalline Al-5083 alloy powders were consolidated using equal channel angular pressing with and without application of back pressure. Physical and mechanical properties such as density and hardness are studied.

Microstructure and Oxidation Resistance of Mechanically Alloyed and Sintered Ni-Nb and Ni-Nb-Ta Alloys

2017 ◽  
Vol 899 ◽  
pp. 19-24
Author(s):  
Lucas Moreira Ferreira ◽  
Stephania Capellari Rezende ◽  
Antonio Augusto Araújo Pinto da Silva ◽  
Gael Yves Poirier ◽  
Gilberto Carvalho Coelho ◽  
...  
Keyword(s):  
Ball Milling ◽  
Oxidation Resistance ◽  
Energy Dispersive Spectrometry ◽  
High Energy ◽  
Milling Process ◽  
Ternary Alloys ◽  
X Ray Diffraction ◽  
Mechanically Alloyed ◽  
Static Oxidation ◽  
Energy Ball

The present work reports on the microstructure and oxidation resistance of Ni-25Nb, Ni-20Nb-5Ta and Ni-15Nb-10Ta alloys produced by high-energy ball milling and subsequent sintering. The sintered samples were characterized by optical microscopy, scanning electron microscopy, X-ray diffraction, energy dispersive spectrometry, and static oxidation tests. Homogeneous microstructures of the binary and ternary alloys indicated the major presence of the β-Ni3Nb compound as matrix, which dissolved large amounts of tantalum. Consequently, the β-Ni3Nb peaks moved toward the direction of smaller diffraction angles. Iron contamination lower than 6.7 at.-% was detected by EDS analysis, which were picked-up during the previous ball milling process. After the static oxidation tests (1100°C for 4 h) the sintered Ni-25Nb, Ni-20Nb-5Ta and Ni-15Nb-10Ta alloys presented mass gains of 31.5%, 30.5% and 28.8%, respectively. Despite the higher densification of the Ni-15Nb-10Ta alloy, the results suggested that the tantalum addition contributed to improve the oxidation resistance of the β-Ni3Nb compound.

Synthesis of Al5083 Alloy by High Energy Ball Mill and Densification through Equal Channel Angular Pressing (ECAP)

2019 ◽  
Vol 969 ◽  
pp. 68-72
Author(s):  
K. Chandra Sekhar ◽  
Balasubramanian Ravisankar ◽  
S. Kumaran
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Ball Mill ◽  
High Energy ◽  
Mechanically Alloyed ◽  
Channel Angle ◽  
Angular Pressing ◽  
High Energy Ball Mill ◽  
Energy Ball ◽  
Scanning Electron

An attempt was made to synthesis Al-5083alloy through high energy ball milling and densification through ECAP. The elemental powders consisting of Al5083 was milled for 5, 10 and 15 hrs using Retsch high energy ball mill (PM400). The physical and structural properties of mechanically alloyed particulates were characterised by diffraction methods and electron microscopy. The 15hrs nanocrystalline structured particulates of Al5083 alloy shows crystallite size of 15nm. Scanning Electron Microscope (SEM) reveals the morphology of alloy which is irregular shaped. The size of alloyed particulates also measured using SEM and found to be 7μm for 15hrs of milling. The 15hr milled alloy particulates were densified by ECAP through 90o die channel angle. Maximum densification of 92% and highest hardness of 63HRB was achieved for sample consolidated with route-A for two passes along with sintering.

Atmosphere effects of the amorphization reaction in NiZr by ball milling

1993 ◽  
Vol 8 (2) ◽  
pp. 307-313 ◽  
Author(s):  
K. Aoki ◽  
A. Memezawa ◽  
T. Masumoto
Keyword(s):  
High Energy ◽  
Hydrogen Atmosphere ◽  
Nitrogen Atmosphere ◽  
Gas Absorption ◽  
X Ray Diffraction ◽  
Mechanically Alloyed ◽  
Scanning Calorimetry ◽  
Transmission Electron ◽  
High Energy Ball Mill ◽  
Energy Ball

An intermetallic compound c–NiZr and a mixture of elemental powders of nickel and zirconium [Ni50Zr50 (at. %)] have been mechanically ground (MG) and mechanically alloyed (MA), respectively, using a high-energy ball mill in various atmospheres. The products were characterized by x-ray diffraction, transmission electron microscopy, differential scanning calorimetry, and chemical analysis as a function of milling time. An amorphous a–NiZr alloy was prepared by both MG and MA in an argon atmosphere. By MG of NiZr, an amorphous nitride a–NiZrN0.15 was synthesized in a nitrogen atmosphere, while a crystalline hydride c–NiZrH3 was formed in a hydrogen atmosphere. On the other hand, ZrN and ZrH2 were formed by MA in a nitrogen and a hydrogen atmosphere, respectively. The amorphization reaction was observed between ZrH2 and Ni by further MA in a hydrogen atmosphere, and a mixture of a–NiZrxHy (x < 1) and ZrH2 was obtained. However, no amorphization was observed by MA between ZrN and Ni in a nitrogen atmosphere. The effects of the milling atmosphere on the phase formations during MG and MA are discussed based on the gas absorption rate.

scholarly journals Influence of Milling Media on the Mechanical Alloyed W-0.5 wt.% Ti Powder Alloy

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Hadi Jahangiri ◽  
Sultan Sönmez ◽  
M. Lütfi Öveçoğlu
Keyword(s):  
Crystallite Size ◽  
Milling Time ◽  
High Energy ◽  
Lattice Parameter ◽  
Mechanically Alloyed ◽  
High Energy Ball Mill ◽  
Powder Density ◽  
Energy Ball ◽  
Ti Powder ◽  
Milled Powders

The effects of milling atmosphere and mechanical alloying (MA) duration on the effective lattice parameter, crystallite size, lattice strain, and amorphization rate of the W-0.5 wt.% Ti powders were investigated. W-0.5 wt.% Ti powders were mechanically alloyed (MA’d) for 10 h and 20 h in a high energy ball mill. Moreover, morphology of the powders for various MA was analyzed using SEM microscopy. Their powder density was also measured by helium pycnometer. The dry milled agglomerated powders have spherical particle, while wet milled powders have layered morphology. Milling media and increasing of milling time significantly reduce the crystallite size. The smallest crystallite size is 4.93 nm which belonged to the dry milled powders measured by Lorentzian method after 20 hours’ MA. However, after 20 hours, MA’d powders show the biggest crystallite size, as big as 57.07 nm, measured with the same method in ethanol.

A Study of Amorphous Erbium-Based Alloys Formed by Near-Isothermal Cold-Rolling of Elemental Composites

1985 ◽  
Vol 58 ◽  
Author(s):  
Michael Atzmon ◽  
Karl M. Unruh ◽  
Constantin Politis ◽  
William L. Johnson ◽  
W. M. Keck
Keyword(s):  
Cold Rolling ◽  
Single Phase ◽  
Enthalpy Of Mixing ◽  
High Energy ◽  
Distribution Functions ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Energy Ball ◽  
Constituent Elements ◽  
Good Agreement

ABSTRACTWe report the formation of single-phase amorphous Cu-Er and Ni-Er alloys in bulk form by cold-rolling of composites prepared from elemental foils. As for previously reported cases of metallic glass formation by solid-state reaction, the driving force for the reaction is the negative enthalpy of mixing of the constituent elements. It occurs during deformation close to room temperature. Amorphous Cu7 2 Er2 8 was also produced by high-energy ball-milling of the elemental powders as well as by sputtering and liquid quenching. The alloys obtained were characterized by means of differential scanning calorimetry and x-ray diffraction. The crystallization behavior observed and the radial distribution functions obtained showed good agreement between the alloys prepared by different methods.

scholarly journals Study of Aluminum Wires Treated with MoB2 Nanoparticles

2018 ◽  
Vol 2 (3) ◽  
pp. 50 ◽  
Author(s):  
David Florián-Algarín ◽  
Angelisse Ramos-Morales ◽  
Michelle Marrero-García ◽  
Oscar Suárez
Keyword(s):  
Pure Aluminum ◽  
High Energy ◽  
Mechanical And Thermal Properties ◽  
X Ray Diffraction ◽  
Electrical Measurements ◽  
Mechanically Alloyed ◽  
Bending Tests ◽  
High Energy Ball Mill ◽  
Energy Ball ◽  
Microstructure Of The Material

This research focuses on the fabrication of aluminum wires treated with MoB2 nanoparticles and their effect on selected mechanical and thermal properties of the wires. These nanoparticles were obtained by fragmentation in a high-energy ball mill and then mechanically alloyed with pure aluminum powder to form Al/MoB2 pellets. The pellets were added to molten pure aluminum (99.5%) at 760 °C. Afterwards, the treated melt was cast into cylindrical ingots, which were cold-formed to the desired final diameter with intermediate annealing. X-ray diffraction and optical microscopy allowed characterizing the structure and microstructure of the material. The wires underwent tensile and bending tests, as well as electrical measurements. Finally, this research demonstrated how the mechanical properties of aluminum wires can be enhanced with the addition of MoB2 nanoparticles with minimal effects on the material resistivity.

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