The Preparation of Mechanically Alloyed Powders for TEM Examination

1987 ◽  
Vol 115 ◽  
Author(s):  
E. A. Kamenetzky ◽  
M. Wall ◽  
R Castro ◽  
L. E. Tanner
Keyword(s):  
High Energy ◽  
Layered Composite ◽  
The Other ◽  
Outer Diameter ◽  
Ion Milling ◽  
Mechanically Alloyed ◽  
Standard Methods ◽  
The Matrix ◽  
Energy Ball ◽  
Cold Pressed

ABSTRACTTEM specimens of mechanically alloyed elemental Ni and Nb powders are prepared by a new procedure. The alloyed powders are mixed with smaller Al powders and fill an aluminum ring (3mm outer diameter). This composite is cold pressed together with the Al powders taking most of the deformation. The compacted specimen can be mechanically thinned. Electropolishing and ion milling can then proceed by standard methods with special precautions to minimize differential polishing or milling rates.The microstructural aspects of the formation of an amorphous phase by high-energy ball milling these powders have been studied. After 6 h each particle transforms to a heterogeneous layered composite of particles of one element in the matrix of the other. Particle size ranges from 15 nm to 90 nm. Mechanical alloying for 36 h results in the formation of an apparently uniform phase interspersed with a few small (4 nm to 30 nm) elemental crystalline particles. The uniformity of composition and the presence of C, O, and Fe were studied by EDX and EELS.

scholarly journals Effect of Milling Parameters on the Development of a Nanostructured FCC–TiNb15Mn Alloy via High-Energy Ball Milling

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1225
Author(s):  
Cristina García-Garrido ◽  
Ranier Sepúlveda Sepúlveda Ferrer ◽  
Christopher Salvo ◽  
Lucía García-Domínguez ◽  
Luis Pérez-Pozo ◽  
...  
Keyword(s):  
Mechanical Alloying ◽  
Ball Mill ◽  
Milling Time ◽  
High Energy ◽  
Planetary Mill ◽  
Nominal Composition ◽  
Mechanically Alloyed ◽  
Milling Parameters ◽  
Energy Ball ◽  
Full Conversion

In this work, a blend of Ti, Nb, and Mn powders, with a nominal composition of 15 wt.% of Mn, and balanced Ti and Nb wt.%, was selected to be mechanically alloyed by the following two alternative high-energy milling devices: a vibratory 8000D mixer/mill® and a PM400 Retsch® planetary ball mill. Two ball-to-powder ratio (BPR) conditions (10:1 and 20:1) were applied, to study the evolution of the synthesized phases under each of the two mechanical alloying conditions. The main findings observed include the following: (1) the sequence conversion evolved from raw elements to a transitory bcc-TiNbMn alloy, and subsequently to an fcc-TiNb15Mn alloy, independent of the milling conditions; (2) the total full conversion to the fcc-TiNb15Mn alloy was only reached by the planetary mill at a minimum of 12 h of milling time, for either of the BPR employed; (3) the planetary mill produced a non-negligible Fe contamination from the milling media, when the highest BPR and milling time were applied; and (4) the final fcc-TiNb15Mn alloy synthesized presents a nanocrystalline nature and a partial degree of amorphization.

Development of Ni/h-BN Self-Lubricating Composite Powder by High-Energy Ball Milling

2016 ◽  
Vol 869 ◽  
pp. 277-282
Author(s):  
Moisés Luiz Parucker ◽  
César Edil da Costa ◽  
Viviane Lilian Soethe
Keyword(s):  
Ball Milling ◽  
Milling Time ◽  
Solid Lubricants ◽  
High Energy ◽  
High Energy Ball Milling ◽  
Second Phase ◽  
Average Particle ◽  
Composite Powders ◽  
The Matrix ◽  
Energy Ball

Solid lubricants have had good acceptance when used in problem areas where the conventional lubricants cannot be applied: under extreme temperatures, high charges and in chemically reactive environments. In case of materials manufactured by powder metallurgy, particles of solid lubricants powders can be easily incorporated to the matrix volume at the mixing stage. In operation, this kind of material provides a thin layer of lubricant that prevents direct contact between the surfaces. The present study aimed at incorporating particles of second phase lubricant (h-BN) into a matrix of nickel by high-energy ball milling in order to obtain a self-lubricating composite with homogeneous phase distribution of lubricant in the matrix. Mixtures with 10 vol.% of h-BN varying the milling time of 5, 10, 15 and 20 hours and their relationship ball/powder of 20:1 were performed. The effect of milling time on the morphology and microstructure of the powders was studied by X-ray diffraction, SEM and EDS. The composite powders showed reduction in average particle size with increasing milling time and the milling higher than 5 hours resulted in equiaxial particles and the formation of nickel boride.

Ball milling for the formation of nanocrystalline intermetallic compounds from Ni-Ti elemental powders

2018 ◽  
Vol 27 (5-6) ◽  
Author(s):  
Pardeep Sharma
Keyword(s):  
Intermetallic Compounds ◽  
Milling Time ◽  
Lattice Strain ◽  
Research Work ◽  
High Energy ◽  
Mechanically Alloyed ◽  
Nano Crystalline ◽  
High Energy Ball Mill ◽  
Productive Process ◽  
Energy Ball

AbstractIn the present research work nickel (Ni) and titanium (Ti) elemental powder with an ostensible composition of 50% of each by weight were mechanically alloyed in a planetary high energy ball mill in diverse milling circumstances (10, 20, 30 and 60 h). The inspection exposed that increasing milling time leads to a reduction in crystallite size, and after 60 h of milling, the Ti dissolved in the Ni lattice and the NiTi (B2) phase was obtained. The lattice strain of ball milled mixtures augmented from 0.15 to 0.45 at 60 h milling. With increase in milling time the morphology of pre-alloyed powder changed from lamella to globular. Annealing of as-milled powders at 1100 K for 800 s led to the formation of NiTi (B19′), grain growth and the release of internal strain. The result indicated that this technique is a powerful and highly productive process for preparing NiTi intermetallic compounds with a nano-crystalline structure and appropriate morphology.

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.

Particle Distribution and Mechanical Properties of Nano-SiCP/Al-Cu Composites

2018 ◽  
Vol 941 ◽  
pp. 2060-2065 ◽  
Author(s):  
Shu Sen Wu ◽  
Jian Yu Li ◽  
Ping An ◽  
Shu Lin Lü
Keyword(s):  
Ultrasonic Vibration ◽  
Metal Matrix ◽  
Particle Distribution ◽  
Acoustic Streaming ◽  
High Energy ◽  
Matrix Composites ◽  
Nanosized Particles ◽  
Cu Alloy ◽  
The Matrix ◽  
Energy Ball

Generally it is difficult to disperse nanosized particles uniformly in metal matrix. In this paper nanoSiC particles reinforced Al-5%Cu matrix composites were prepared by molten-metal process, combined with high energy ball-milling and ultrasonic vibration methods. Ultrasonic vibration treatment (UV) has been successfully used to disperse the particles distribution of nanoSiCp particles in the matrix. Big aggregates of particles are eliminated by the effects of cavitation and the acoustic streaming of UV for 1 min. All the particles aggregates are eliminated and the particles are uniformly distributed in the melt after treated by UV for 5 min. The refinement of Al2Cu phase in Al-Cu alloy is more obvious and more uniform distributed with the increase of UV time. The ultimate tensile strength (UTS), yield strength and elongation of the 1wt% nanosized SiCp/Al-5Cu composites treated by UV for 5 min are increased by 37%, 9.5% and 270% respectively, compared with the untreated composites.

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.

scholarly journals Crystal Structure Evolution, Microstructure Formation, and Properties of Mechanically Alloyed Ultrafine-Grained Ti-Zr-Nb Alloys at 36≤Ti≤70 (at. %)

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 587 ◽  
Author(s):  
Marczewski ◽  
Miklaszewski ◽  
Maeder ◽  
Jurczyk
Keyword(s):  
Crystal Structure ◽  
Mechanical Alloying ◽  
Pure Titanium ◽  
Young Modulus ◽  
High Energy ◽  
Structure Evolution ◽  
X Ray Diffraction ◽  
Mechanically Alloyed ◽  
Ultrafine Grained ◽  
Energy Ball

Titanium β-type alloys are preferred biomaterials for hard tissue replacements due to the low Young modulus and limitation of harmful aluminum and vanadium present in the commercially available Ti6Al4V alloy. The aim of this study was to develop a new ternary Ti-Zr-Nb system at 36≤Ti≤70 (at. %). The technical viability of preparing Ti-Zr-Nb alloys by high-energy ball-milling in a SPEX 8000 mill has been studied. These materials were prepared by the combination of mechanical alloying and powder metallurgy approach with cold powder compaction and sintering. Changes in the crystal structure as a function of the milling time were investigated using X-ray diffraction. Our study has shown that mechanical alloying supported by cold pressing and sintering at the temperature below α→β transus (600°C) can be applied to synthesize single-phase, ultrafine-grained, bulk Ti(β)-type Ti30Zr17Nb, Ti23Zr25Nb, Ti30Zr26Nb, Ti22Zr34Nb, and Ti30Zr34Nb alloys. Alloys with lower content of Zr and Nb need higher sintering temperatures to have them fully recrystallized. The properties of developed materials are also engrossing in terms of their biomedical use with Young modulus significantly lower than that of pure titanium.

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