Microstructural evolution in mechanically alloyed Nb-25 at.% Ge

1986 ◽  
Vol 44 ◽  
pp. 556-557
Author(s):  
E.A. Kenik ◽  
R.B. Bayuzick ◽  
M.S. Kim ◽  
C.C. Koch
Keyword(s):  
Mechanical Alloying ◽  
Microstructural Evolution ◽  
Rapid Heating ◽  
High Energy ◽  
Mechanically Alloyed ◽  
Heating And Cooling ◽  
High Energy Ball Mill ◽  
Powder Particles ◽  
Energy Ball ◽  
Germanium Powder

Mechanical alloying involves the mixing and milling of compositionally different powders in a high energy ball mill. During this process, powder particles cold-weld to others upon impact and subsequently fracture. The coldwelding (which may involve local melting or at least elevated temperature just after impact) produces a zone of intermediate composition. As a result of the rapid heating and cooling of the interdiffused zone and the large amount of strain energy stored in the powder, mechanical alloying may produce metastable materials. The current study involves the microstructural evolution in mechanically alloyed elemental niobium and germanium powder blends.

Structure and Magnetic Properties of Ternary Nanosized FeAlSn and CuFeCo Powders Synthesized by Mechanical Milling

2017 ◽  
Vol 47 ◽  
pp. 79-88 ◽  
Author(s):  
Z. Hamlati ◽  
W. Laslouni ◽  
Mohammed Azzaz ◽  
M. Zergoug ◽  
D. Martínez-Blanco ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Crystallite Size ◽  
Milling Time ◽  
Magnetic Measurements ◽  
High Energy ◽  
X Ray Diffraction ◽  
Mechanically Alloyed ◽  
High Energy Ball Mill ◽  
Powder Particles ◽  
Energy Ball

Ternary Fe72Al26Sn2 and Cu70Fe18Co12 alloys were obtained by mechanical alloying of pure Fe, Al, Sn, Cu and Co powders using a high energy ball mill. X-ray diffraction and electron microscopy supported by magnetic measurements have been applied to follow changes in the microstructure, phase composition and magnetic properties in dependence on milling time. With the increase of milling time all Al and Sn atoms dissolved in the bcc Fe and the final product of the MA process was the nanocrystalline Fe (Al, Sn) solid solution in a metastable state with a large amount of defects and mean crystallite size of 5 nm. However, the obtained crystallite size value is about 10 nm for the ball milled Cu70Fe18Co12 powders. The electron microscope observations show the morphology of powder particles. Magnetic properties of the nanocrystalline mechanically alloyed FeAlSn and CuFeCo were also investigated and were related to the microstructural changes.

Mechanical Alloying of Ti-Based Materials

2018 ◽  
Vol 770 ◽  
pp. 95-105 ◽  
Author(s):  
Hilda Chikwanda ◽  
L. Mahlatji
Keyword(s):  
Mechanical Alloying ◽  
Powder Processing ◽  
High Energy ◽  
Processing Technique ◽  
Dispersion Strengthening ◽  
High Energy Ball Mill ◽  
Potential Applications ◽  
Powder Particles ◽  
Energy Ball ◽  
Metastable Effects

Mechanical alloying (MA) is a simple and versatile dry powder processing technique that has been used for the manufacture of both equilibrium and metastable phases of commercially useful and scientifically interesting materials. It owes its origin to an industry need to develop a nickel-based super alloy for gas turbine applications that had both oxide dispersion strengthening and precipitation hardening. This far-from equilibrium powder metallurgy processing technique involves fracturing, welding and re-welding of powder particles in a High Energy Ball Mill (HEBM). MA is an economically viable process with important technical advantages. Its utmost advantage is in the synthesis of novel alloys, e.g., alloying of ordinarily immiscible elements, that is not possible by any other technique. As MA is a completely solid-state processing technique, the limitations imposed by phase diagrams do not apply to it. The MA process is capable of producing different types of metastable effects in a variety of alloy systems. Some of the metastable effects achieved by MA are solid solution formation and amorphisation. MA has the possibility of producing superior and enhanced materials than those produces by conventional methods. In this work a review of MA and its present and potential applications for Ti-based materials are presented.

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.

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.

SYNTHESIS OF NANO-CRYSTALLINE Cu-Cr ALLOY BY MECHANICAL ALLOYING

2012 ◽  
Vol 05 ◽  
pp. 496-501 ◽  
Author(s):  
S. SHEIBANI ◽  
S. HESHMATI-MANESH ◽  
A. ATAIE
Keyword(s):  
Mechanical Alloying ◽  
Structural Evolution ◽  
High Energy ◽  
Lattice Parameter ◽  
Control Agent ◽  
Milling Process ◽  
X Ray Diffraction ◽  
Nano Crystalline ◽  
High Energy Ball Mill ◽  
Energy Ball

In this paper, the influence of toluene as the process control agent (PCA) and pre-milling on the extension of solid solubility of 7 wt.% Cr in Cu by mechanical alloying in a high energy ball mill was investigated. The structural evolution and microstructure were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques, respectively. The solid solution formation at different conditions was analyzed by copper lattice parameter change during the milling process. It was found that both the presence of PCA and pre-milling of Cr powder lead to faster dissolution of Cr . The mean crystallite size was also calculated and showed to be about 10 nm after 80 hours of milling.

Effect of Boron on the Amorphization of Zr-Ti-Ni-Cu Alloy

1994 ◽  
Vol 38 ◽  
pp. 763-767
Author(s):  
J. D. Makinson ◽  
R. J. De Angelis ◽  
S. C. Axtell
Keyword(s):  
Mechanical Alloying ◽  
Weight Percent ◽  
High Energy ◽  
Mechanically Alloyed ◽  
Crystalline Materials ◽  
Powder Consolidation ◽  
Cu Alloy ◽  
Structure Changes ◽  
Powder Particles ◽  
New Compounds

Abstract The mechanical alloying process continually deforms, cold welds, and breaks apart metal powder particles. During the process of mechanical alloying elemental crystalline powders can produce an amorphous alloyed powder. Consolidation of these powders by powder metallurgy techniques can produce amorphous bulk metals. Two Alloys 62.24 Zr-10.89 Ti-9.71 Ni-13.14 Cu-4.02 B and 64.84 Zr-11.35 Ti-11.12 Nt-13.69 Cu weight percent were mechanically alloyed for 45 hours by a SPEX 800 high energy ball-mill. The changes in structure were monitored by X-ray diffraction after every 5 hours of milling. Both powder compositions became amorphous after 15 hours of milling. New compounds began to form during milling to 35 hours. Milling for longer times produced no further structure changes. The milled samples were annealed at 950°C for 1 hour which produced a complex set of crystalline materials. The crystalline phases containing boron have larger lattice parameters and less tendency for grain growth.

Technological Aspects of Fe-Al-Si Intermetallic Alloy Preparation by Mechanical Alloying

2019 ◽  
Vol 810 ◽  
pp. 101-106 ◽  
Author(s):  
Petr Haušild ◽  
Jaroslav Čech ◽  
Veronika Kadlecová ◽  
Miroslav Karlík ◽  
Filip Průša ◽  
...  
Keyword(s):  
Mechanical Alloying ◽  
Ball Mill ◽  
High Energy ◽  
Intermetallic Alloy ◽  
Alloyed Powder ◽  
Temperature Oxidation ◽  
High Energy Ball Mill ◽  
Speed Up ◽  
Energy Ball ◽  
Kinetics Of

In this paper, recently developed ternary FeAl20Si20 (wt.%) alloy with promising high-temperature oxidation and wear resistance was prepared by mechanical alloying in a high-energy ball mill. The possibility to speed-up the mechanical alloying process by replacing aluminium (and partly silicon) elemental powder by the pre-alloyed powder (AlSi30) with relatively fine dispersion of Si in the Al-Si eutectic was examined. The microstructure, phase composition and mechanical properties after various time of mechanical alloying were characterized. The effect of using the pre-alloyed powders on kinetics of mechanical alloying is compared with the results obtained on batches prepared from elemental powders.

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.

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