nanocrystalline metals prepared by high energy ball milling

The nanocrystalline cubic SiC phase is prepared by mechano-synthesis of stoichiometric mixture of Si and graphite powders under argon in a high-energy ball mill. Formation of the thin graphite layer and amorphous Si are noticed within 3 h of milling.

Nanocrystalline metals prepared by high-energy ball milling Fecht, H. J. Hellstern, E. Fu, Z. Johnson, W. L. Abstract This is a first systematic report on the synthesis of completely nanocrystalline metals by high-energy deformation processes.

The atomic-scale structure of nanocrystalline ZrO 2 obtained by ball milling has been studied using high-energy x-ray diffraction and the atomic pair distribution function technique. The studies show that, upon relatively short milling times, the parent crystalline material, monoclinic ZrO 2, evolves into a nanocrystalline phase that is locally similar to …

12%Pure metals with body-centered cubic (bcc) and hexagonal close-packed (hcp) structures are subjected to ball milling, resulting in a decrease of the average grain size to ≈9 nm for metals with bcc and to ≈13 nm for metals with hcp crystal structures.

the objectives of the present work are (i) to produce nanocrystalline (ti 0.8 w 0.2 )c by high-energy ball milling the elemental ti, w and c (graphite) powders at room temperature, (ii) to characterize the microstructure evolution of the prepared materials in terms of crystallite size and strain and (iii) finally to explain the relationship …

The high energy milling was performed at 1000 rpm for 2 h. The as-milled powders were highly agglomerated with a low SSA (<4 m 2 /g). A second milling step with lower energy and different milling times was performed in order to increase the specific surface area. A laboratory attritor containing 4.5 mm hardened steel balls was used in this step.

Nanocrystalline non-stoichiometric cadmium ferrite (CdFe2O4) has been synthesized by high-energy ball milling the mixture (1:1 mol%) of CdO and α-Fe2O3 at room temperature.

Abstract: Ultrafine MgH2 nanocrystalline powders were prepared by reactive ball milling of elemental Mg powders after 200 h of high-energy ball milling under a hydrogen gas pressure of 50 bar. The as-prepared metal hydride powders were contaminated with …

Conclusion. α -Fe 2 O 3 nanocrystalline was successfully prepared by high-energy ball milling of goethite ( α -FeOOH) powder after 40 hours of milling. The mechanochemical effect induced by high energy ball milling induced dehydration and transformation of goethite to hematite. This work shows that this method is environmentally …

Nanocrystalline and microcrystalline Fe-10Cr alloys were prepared by high energy ball milling followed by compaction and sintering and then oxidized in air for 52 hours at 350°C. The oxidation resistance of nanocrystalline alloy as determined by measuring the weight gain after regular time intervals was compared with that of the ...

Goethite nanocrystallines powders were prepared by high-energy ball milling with a balls-to-powder mass ratio of 10:1 and for 40 h of milling. X-ray diffraction, Rietveld analysis, and vibrating sample magnetometer are used to characterize the obtained nanopowders followed by tests for toxic metals removal from aqueous solutions.

Nanocrystalline Mg2Ni powders produced by high energy ball milling (HEBM) were subjected to further severe plastic deformation by cold rolling (CR) or equal-channel angular pressing (ECAP). The microstructure of the alloys have been analysed by the Convolutional whole profile fitting method of the X-ray line profiles. The hydrogenation behavior has been studied by …

Abstract A novel grain refiner consisting of nanoparticulate TiN suspended in a Ti metal powder (abbr. TiN/Ti refiner) was prepared by high energy ball milling. The effect of the TiN/Ti refiner addition contents on microstructures and properties of Al-Zn-Mg-Cu alloy was investigated in detail. The results show that the TiN/Ti refiner addition changes the α(Al) matrix morphology of …

To investigate mechanical properties and deformation mechanisms of nanocrystalline materials under high strain rate, dynamic impact tests for nanocrystalline Ni bulk prepared by high-energy ball milling combined with compaction and hot-pressure sintering were carried out under different high strain rates on Split Hopkinson bar.

U.S. Department of Energy Office of Scientific and Technical Information. Search terms: ... Atomic-scale structure of nanocrystalline ZrO{sub 2} prepared by high-energy ball milling. Atomic-scale structure of nanocrystalline ZrO{sub 2} prepared by high-energy ball milling. Full Record;

The mechanical alloying experiments were performed using a faro-planetary high-energy ball mill (Retsch PM 400). In order to ensure that the milling will be performed in an inert atmosphere (no oxidation during the milling), the starting powders with five (05) stainless steel balls, having 12 mm in diameter, were sealed in atmosphere of azote ...

12%We prepared various nanocrystalline ceramics by high-energy ball milling. The investigated systems are the oxide ceramics Li 2 O, LiNbO 3, LiBO 2, B 2 O 3, TiO 2 as monophase materials and the composite material Li 2 O : B 2 O 3. The average grain size was adjusted by variation of the milling time.

On the other hand, the milling time is directly related to energy use as well as the purity of the obtained powder products. This paper presents the results of investigation on some typical properties of nanocrystalline iron powders prepared by milling techniques using a Fritsch P-6 planetary ball miller.

For all nanocrystalline materials prepared by high-energy ball milling synthesis route, surface and interface contamination is a major concern. In particular, mechanical attributed contamination by the milling tools (Fe or WC) as well as ambient gas (trace impurities such as O 2, N 2 in rare gases) can be problems for high-energy ball milling.

Nanocrystalline Metals Prepared by High-Energy Ball Milling H.J. FECHT, E. HELLSTERN, Z. FU, and W.L. JOHNSON This is a first systematic report on the synthesis of completely nanocrystalline metals by high-energy deformation processes. Pure metals with body-centered cubic (bcc) and hexagonal

The microstructure and magnetic properties of nanocrystalline Fe-Si soft magnetic material fabricated by high energy vibratory milling are investigated. Fe-Si × wt% (x = 1.78, 3.51, 3.80, 5.08, 6.06, 6.98, 8.04) compositions are studied, with the 3.5 wt% case being used as a model system to investigate effects of processing time. X-ray diffraction (XRD) measurements …

High energy ball milling (HEBM) is another promising synthesis route capable of synthesizing nanostructured mixed oxides at quasi room temperature. Mechanical impact during the process reduces the precursors' crystallite size to nano scale, provides a homogeneous mixture, and enhances the solid state diffusion.

This paper reports a study on nanocrystalline ceria powder prepared by high energy ball-milling and combustion syn-thesis methods. The combustion synthesis was carried out using ceric ammonium nitrate as oxidizer and citric acid, glycine or citric acid plus glycine as fuel. The minimum crystallite size of ceria powder is obtained by combustion syn-

In this current study, nanocrystalline Dy powders were prepared by melt-spinning and subsequent high-energy ball-milling. The effect of ball-milling time on the structure and magnetic properties of the powders was studied. The crystal structure and microstructure of the melt-spun ribbons and ball-milled powders were observed by X-ray …

The hydrogen loading characteristics of nanocrystalline Mg, Mg–Ni (Ni from 0.1 to 10 at.%), and Mg–Fe (Fe from 1 to 10 at.%) alloys in 3 MPa H2 were examined using high pressure differential scanning calorimetry and thermogravimetric analysis. All samples showed rapid uptake of hydrogen. A decrease in the onset temperature for hydrogen absorption was …

Electrical and magnetic properties of nanocrystalline BiFeO3 prepared by high energy ball milling and microwave sintering. Prasad ChS(1), Sreenivasulu G, Kiran SR, Balasubramanian M, Murty BS. Author information: (1)Department of Metallurgical and Materials Engineering, Indian Institute of Technology, Madras, Chennai 600036, India.

Thermal stability of nanocrystalline Al-5at.%Ni and Al-5at.%V alloys produced by high-energy ball milling journal, May 2018 Esquivel, J.; Wachowiak, M. G.; O'Brien, S. P. Journal of Alloys and Compounds, Vol. 744

The influence of low energy ball milling on the crystallite size, lattice strain, and storage of deformation energies of elemental metal powders is studied. The formation of nanosized grains (5–25 nm) and enhancement of lattice strain up to 0.4% is found. Excess enthalpies of up to 25% of the heat of fusion are reached.

In this present work, nanodiamond (ND) particles were successfully prepared from commercial micron diamond powder at room temperature by high energy ball milling process using an oscillatory mill (SPEX8000). The size reduction and structural evolutions of the milled samples were investigated as a function of the milling time by means of X-ray diffraction, and field …

Nanocrystalline metal powders synthesized by mechanical alloying in a ball mill resulted in micron-sized powder particles with a nanosized (5 to 25 nm) substructure. ... {sub 2}-(Al,Cr){sub 3}Ti intermetallic compounds, which were prepared by high energy ball milling, was analyzed. Particular attention was paid to the development of the ...