amorphization by ball milling a review

Amorphization by ball milling. A review - ScienceDirect

Oct 01, 1988  Physica B 153 (1988) 93-135 North-Holland, Amsterdam AMORPHIZATION BY BALL MILLING. A REVIEW A.W. WEEBER and H. BAKKER Natuurkundig Laboratoriurn der Universiteit van Amsterdam, Valckenierstraat 65, NL-IOI8 XE Amsterdam, The Netherlands" Received 1 March 1988 A new method for the preparation of amorphous alloys is the mechanical alloying process.

Get PriceEmail contact

Amorphization by ball milling. A review - ScienceDirect

A new method for the preparation of amorphous alloys is the mechanical alloying process. So far, three amorphization reaction types were observed when this technique is used. Which reaction type occurs depends on the local conditions during the milling, such as

Get PriceEmail contact

Amorphization by ball milling. A review - NASA/ADS

Oct 01, 1988  Amorphization by ball milling. A review Weeber, A. W.; Bakker, H. Abstract. A new method for the preparation of amorphous alloys is the mechanical alloying process. So far, three amorphization reaction types were observed when this technique is used.

Get PriceEmail contact

(PDF) AMORPHIZATION OF SEMICONDUCTORS BY BALL-MILLING

This suggests that amorphization in metal-metalloid systems, i.e. ductile-brittle systems, like Fe40Ni40P14B6 is fully achieved by ball milling alone using high milling energy and metalloid ...

Get PriceEmail contact

Amorphization mechanisms of NiZr2 by ball-milling ...

The microstructure of NiZr 2 in the course of amorphization by ball-milling is studied by transmission electron microscopy (TEM) and x-ray diffraction (XRD). The evolution from the initial fully crystalline alloy to a fully amorphized material is described. It is shown that prior to amorphization, the powder aggregates achieve a 100% nanocrystalline structure; the amorphous phase then appears ...

Get PriceEmail contact

Ball-milling-induced amorphization in Ni x Zr y compounds ...

Jul 01, 1993  A vibrating frame grinder has been instrumented for evaluating the amplitude and frequency of ball oscillation, as a function of the amplitude of vibration of the frame and of the ball mass. Based on such measurements, it is found that Ni x Zr y compounds become fully amorphized provided the specific milling intensity is greater than a temperature- and composition-dependent threshold value.

Get PriceEmail contact

(PDF) Amorphization of Aluminum Base Multicomponent ...

The alloys were ground by a planetary ball mill for 2 h in order to obtain a fine powder. The Mg-23.5Ni-5Cu alloy had crystalline Mg and Mg2Ni phases. Mg-23.5Ni-5Cu had an effective hydrogen ...

Get PriceEmail contact

Amorphization by mechanical alloying - ScienceDirect

Feb 01, 1990  Johnson7 has reviewed the fundamental thermo- dynamics and kinetic factors of amorphization in metallic systems with emphasis placed on the me- chanisms for solid-state amorphization. Weeber and Bakker8 have recently reviewed amorphization by ball milling. Two major categories of amorphization by ball milling can be identified: 1.

Get PriceEmail contact

Amorphization of single composition powders by mechanical ...

Jan 01, 1996  Phenomenology of Amorphization by MM Amorphization by MM consists of energizing the crystalline solid by the severe cyclic deformation that ball-milling provides. It is significant that ball-milling has been found to induce extensive plastic deformation even into extremely brittle materials such as A 15 intermetallic compounds like 'hn^Sn (6).

Get PriceEmail contact

Overview of milling techniques for improving the ...

Jul 01, 2015  Ball milling of pure drug mixtures have also been investigated. More recently, ball milling of a combination of two BCS Class II drugs, simvastatin and glipizide, resulted in the formation of stable co-amorphous mixtures . Despite the efficiency of ball milling for size reduction or amorphization, it is less amendable to scale up.

Get PriceEmail contact

Amorphization of selenium induced by high-energy ball milling

Structural changes occurring in the crystalline element selenium upon high-energy ball milling has been studied. Milling experiments have been performed at the ambient temperature and at a cryogenic temperature of -100 \ifmmode^\circ\else\textdegree\fi{}C, respectively. The final milling products under both conditions were found to be a fully amorphous phase after several hours of mechanical ...

Get PriceEmail contact

Amorphization mechanisms of NiZr2 by ball-milling ...

The microstructure of NiZr 2 in the course of amorphization by ball-milling is studied by transmission electron microscopy (TEM) and x-ray diffraction (XRD). The evolution from the initial fully crystalline alloy to a fully amorphized material is described. It is shown that prior to amorphization, the powder aggregates achieve a 100% nanocrystalline structure; the amorphous phase then appears ...

Get PriceEmail contact

Destruction, Amorphization and Reactivity of Nano-BN

The BN destruction and amorphization under ball milling. Fig. 2 shows the dependence of specific surface area measured by BET on the dose of mechanical treatment. At the initial stage of mechanical treatment specific surface area increases with increase of the dose, reaches maximum of about 400m. 2 /g (at the dose of

Get PriceEmail contact

Amorphization and disordering of the Ni3Al ordered ...

Effect of ball-to-powder weight ratio on the amorphization reaction of Al50Ta50 by ball milling. Journal of the Less Common Metals, Vol. 169, Issue. 2, p. 235.

Get PriceEmail contact

Amorphization of single composition powders by mechanical ...

Jan 01, 1996  Phenomenology of Amorphization by MM Amorphization by MM consists of energizing the crystalline solid by the severe cyclic deformation that ball-milling provides. It is significant that ball-milling has been found to induce extensive plastic deformation even into extremely brittle materials such as A 15 intermetallic compounds like 'hn^Sn (6).

Get PriceEmail contact

Amorphization by mechanical alloying - ScienceDirect

Feb 01, 1990  Johnson7 has reviewed the fundamental thermo- dynamics and kinetic factors of amorphization in metallic systems with emphasis placed on the me- chanisms for solid-state amorphization. Weeber and Bakker8 have recently reviewed amorphization by ball milling. Two major categories of amorphization by ball milling can be identified: 1.

Get PriceEmail contact

Amorphization of ZrO 2 + CeO 2 Powders Through Mechanical ...

To prepare the powder for the use of the kinetic spray, the amorphization and grain refinement of ZrO 2 powder in mechanical ball milling were studied. The results showed that the amorphization and grain refinement were improved because of the formation of solid solution when the CeO 2 agent was added. Subsequently, a nearly spherical powder ...

Get PriceEmail contact

Disordering and amorphization of L12-type alloys by ...

This is in contrast to the Zr 3 Al compound (also L1 2-type) for which a short milling time is sufficient for obtaining complete amorphization. Variations in the aptitudes toward amorphization of the three L1 2 -type alloys under ball-milling conditions are attributed in part to the differences in the lattice stability terms of their disordered ...

Get PriceEmail contact

Overview of milling techniques for improving the ...

Jul 01, 2015  Ball milling of pure drug mixtures have also been investigated. More recently, ball milling of a combination of two BCS Class II drugs, simvastatin and glipizide, resulted in the formation of stable co-amorphous mixtures . Despite the efficiency of ball milling for size reduction or amorphization, it is less amendable to scale up.

Get PriceEmail contact

Mechanical Milling: a Top Down Approach for the Synthesis ...

Feb 03, 2012  Touzik et al[102] studied the structural transformations and amorphization of graphite upon high-energy ball-milling under argon and hydrogen atmosphere.Up to approximately 40% of the adsorbed nitrogen was stored in ultra micropores with diameter less than 0.8 nm and it was independent from milling atmosphere.

Get PriceEmail contact

Enhanced Amorphization by Sn Substitution for Si and B in ...

Enhanced Amorphization by Sn Substitution for Si and B in the Ball-Milled Ti 50 Ni 22 Cu 18 Al 4 Si 4 B 2 Alloy p.488. Electron Structure, Stability and Nanocrystallization of Al - Based Amorphous Alloys p.494. Local Order Changes in Amorphous Zr ...

Get PriceEmail contact

(PDF) Amorphization behaviour in mechanically alloyed Ni ...

Amorphization behaviour of NixTa100–x alloy powders synthesized by mechanical alloying mixtures of pure crystalline Ni and Ta powders with a Spex high energy ball mill was studied.

Get PriceEmail contact

(PDF) Amorphization of the prototypical zeolitic ...

Partial amorphization of the ZIF-backbone by ball-milling results in significant enhancement of the composite stability towards exposure to ambient conditions, up to 20 days.

Get PriceEmail contact

Formation of physically stable amorphous drugs by milling ...

Dec 30, 2002  Ball milling the drugs alone for 48 h resulted in no amorphization. X‐ray powder diffractometry (XPD), birefringence, and differential scanning calorimetry (DSC) data indicated amorphization of all the four drugs on ball milling with Neusilin.

Get PriceEmail contact

Destruction, Amorphization and Reactivity of Nano-BN

The BN destruction and amorphization under ball milling. Fig. 2 shows the dependence of specific surface area measured by BET on the dose of mechanical treatment. At the initial stage of mechanical treatment specific surface area increases with increase of the dose, reaches maximum of about 400m. 2 /g (at the dose of

Get PriceEmail contact

Amorphization reactions during mechanical alloying/milling ...

Jul 01, 1990  Solid-state amorphization reactions resulting from the severe mechanical deformation obtained by high-energy ball milling are reviewed. Two classes of such reactions are discussed: 1. “mechanical alloying” where material transfer occurs between elemental powders or alloys, and 2. “mechanical milling” where an equilibrium crystalline intermediate phase is transformed to the

Get PriceEmail contact

Amorphization Induced by Ball — Milling in Some Pure ...

Abstract. We report on the crystal to amorphous phase transition induced by ball — milling in pure Si and pure Ge powders. Based on X-ray diffraction patterns, scanning and transmission electron micrographs, EDX microanalyses, differential thermal analyses and differential scanning calorimetry, it seems that amorphization occurs during the continuous decrease of the particle grain size and ...

Get PriceEmail contact

BALL MILLING AMORPHIZATION IN A VIBRATING FRAME

for ball milling amorphization of NiloZr7, much in the same way as in ref. /l/; comparing the milling conditions for amorphization under both types of milling (planetary and vibrating frame) will help choosing the proper control parameters of the dynamical state of the alloy under milling. ...

Get PriceEmail contact

Amorphization of single composition powders by mechanical ...

Jan 01, 1996  Phenomenology of Amorphization by MM Amorphization by MM consists of energizing the crystalline solid by the severe cyclic deformation that ball-milling provides. It is significant that ball-milling has been found to induce extensive plastic deformation even into extremely brittle materials such as A 15 intermetallic compounds like 'hn^Sn (6).

Get PriceEmail contact

Effect of ball-to-powder weight ratio on the amorphization ...

May 01, 1991  The present study was undertaken in order to elucidate the effect of the ball-to-powder weight ratio on the amorphization reaction of Al 50 Ta 50 alloy powders using the ball milling technique. As the ball-to-powder weight ratio increases, the rate of amorphization reaction increases drastically, but the content of iron contamination, which comes from the milling tools, increases sharply.

Get PriceEmail contact

Amorphization of ZrO 2 + CeO 2 Powders Through Mechanical ...

To prepare the powder for the use of the kinetic spray, the amorphization and grain refinement of ZrO 2 powder in mechanical ball milling were studied. The results showed that the amorphization and grain refinement were improved because of the formation of solid solution when the CeO 2 agent was added. Subsequently, a nearly spherical powder ...

Get PriceEmail contact

Disordering and amorphization of L12-type alloys by ...

This is in contrast to the Zr 3 Al compound (also L1 2-type) for which a short milling time is sufficient for obtaining complete amorphization. Variations in the aptitudes toward amorphization of the three L1 2 -type alloys under ball-milling conditions are attributed in part to the differences in the lattice stability terms of their disordered ...

Get PriceEmail contact

Enhanced Amorphization by Sn Substitution for Si and B in ...

Enhanced Amorphization by Sn Substitution for Si and B in the Ball-Milled Ti 50 Ni 22 Cu 18 Al 4 Si 4 B 2 Alloy p.488. Electron Structure, Stability and Nanocrystallization of Al - Based Amorphous Alloys p.494. Local Order Changes in Amorphous Zr ...

Get PriceEmail contact

Solid State Amorphization of Pharmaceuticals Molecular ...

Oct 27, 2008  Amorphous solids are conventionally formed by supercooling liquids or by concentrating noncrystallizing solutes (spray-drying and freeze-drying). However, a lot of pharmaceutical processes may also directly convert compounds from crystal to noncrystal which may have desired or undesired consequences for their stability. The purpose of this short review paper is (i) to illustrate the ...

Get PriceEmail contact

Athermal character of the solid state amorphization of ...

In this paper, we report the possibility to reach pure glassy amorphous lactose by ball milling of crystalline α lactose under a dry nitrogen atmosphere. This route to the glassy state is found to be free of mutarotation towards the anomer β while this mutarotation is unavoidable using the usual thermal route, i.e. the quench of the liquid. This result definitely makes the 'local quench ...

Get PriceEmail contact

Formation of physically stable amorphous drugs by milling ...

Dec 30, 2002  Ball milling the drugs alone for 48 h resulted in no amorphization. X‐ray powder diffractometry (XPD), birefringence, and differential scanning calorimetry (DSC) data indicated amorphization of all the four drugs on ball milling with Neusilin.

Get PriceEmail contact

Ball-milling-induced amorphization in ... - Physical Review B

Ball-milling-induced amorphization in Ni x Zr y compounds: A parametric study Y. Chen, M. Bibole, R. Le Hazif, and G. Martin Phys. Rev. B 48 , 14 – Published 1 July 1993

Get PriceEmail contact

HRTEM and EELS Studies on the Amorphization of Hexagonal ...

The amorphization kinetics are revealed by X‐ray diffractometry (XRD), high‐resolution transmission electron microscopy (HRTEM), and electron energy loss spectroscopy (EELS). HRTEM investigations indicate that, in the early stage of milling, the thick sp 2 layers are sliced into many thinner sheets because of cleavage along the basal planes.

Get PriceEmail contact

Copyright © 2020.Company name All rights reserved.SiteMap