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.
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.
We discover that this guest retention is greatly enhanced upon facile amorphisation by ball milling, particularly in the case of ZIF-mnIm, for which I 2 loss is retarded by as much as 200 °C. It is anticipated that this general approach should be applicable to the wide range of available metal–organic framework-type materials for the ...
Pure Co powder charge was milled under argon atmosphere at milling speed of 770 rpm for 30 hours (h). Milling was performed in the stainless steel milling medium consisting of 5 mm diameter balls and vial at ball-to-powder ratio of 20 : 1. Milling vial was equipped with cooling system to avoid heating during milling.
An intermetallic compound c –NiZr and a mixture of elemental powders of nickel and zirconium [Ni 50 Zr 50 (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 …
Due to the complicated ball milling environment, how the nanoscale microstructure evolutes during the ball milling in various materials is still under discussion, and some conclusions on the final phases after ball milling are controversial, especially in the field of solid-state amorphization caused by ball milling [3,4].
LATTICE INSTABILITY IN THE SOLID-STATE AMORPHIZATION OF FE(AL) SOLID SOLUTIONS BY MECHANICAL ALLOYING[J].Physical Review.B.Condensed Matter,1997(5):2302-2305. [18] Sheng H W;XU J;SUN X K et al.A nanocomposite of Alg5In5 synthesized by ball milling[J].Nanostructured Materials,1995,6:417-420.
Amorphization scenarios in multiparticulate grinding media composed of As 4 S 4 /ZnS/Fe 3 O 4 nanocomposites driven by high-energy ball mechanical milling are identified employing the X-ray powder diffraction analysis on intermediate-range ordering in the generated amorphous phase. This amorphous phase is supposed to be nucleated heterogeneously from …
After preparation of DCPD by wet chemistry, the material was dry milled in an Attritor high energy process (at 400 RPM) during 20 minutes. Experiments were also conducted using a regular ball milling process at 15 and 30h residence time. Amorphization of DCPD confirmed using FTIR, XRD and 31 P solid-states NMR (cross-polarization and decoupling).
Changes in the physicochemical properties in the amorphization process of atorvastatin by ball milling. Figure 1 shows the XRD profiles of AT at various milling times. The patterns suggested that the intensities of the diffraction peaks of the crystalline sample were reduced with elapsing milling time, and all peaks disappeared at over 30 min ...
A planetary ball mill and two types of substrates were used in order to deposit Ni-Nb amorphous coating. • The coating formed on the disc substrate had a higher volume fraction of amorphous phase and was thicker than the coating on the cubic substrate. Abstract
10%Amorphization of metallic titanium by ball milling was presented. With the introduction of continuous pickup of impurities, hexagonally close-packed (hcp) titanium transformed gradually into an amorphous phase without experiencing any intermediate stage of forming a detectable metastable compound phase. The crystallization …
Mechanical alloying (MA) of iron and graphite was performed for C-10 at%Fe alloy by the use of a conventional ball mill. The structure of mechanically alloyed samples were examined by X-ray diffraction, transmission electron microscopy. A spectrometric approach to the change of structure during the milling process was carried out by carbon Kα X-ray-emission band spectroscopy …
X-ray diffraction has been used to investigate the kinetics of amorphization through ball-milling at 20 Hz, for five zeolitic imidazolate frameworks (ZIFs) – ZIF-8, ZIF-4, ZIF-zni, BIF-1-Li and CdIF-1. We find that the rates of amorphization for the zinc-containing ZIFs increase with increasing solvent acces In celebration of Tony Cheetham's 70th birthday Flexibility and Disorder in Metal ...
Zeolite X, synthetic mordenite and zeolite A in which a part of the original sodium ions has been exchanged by other cations (Li +, K +, Cs +) were investigated by means of simultaneous thermal analysis, before and after mechanochemical amorphization by ball milling.In all the examined cases, the initial rate of dehydration of amorphized sample was …
Recently, cyclic transformations in which amorphization and crystallization occur sequentially have been observed under continuous ball milling. It is shown that this phenomenon does not have obvious analogs with the periodic redox reactions or with diffusive-reactive phenomena known in chemistry.
[17] Weeber A W and Bakker H 1988 Amorphization by ball milling—a review Physica B 153 93–135. Go to reference in chapter Crossref [18] Hong L B and Fultz B 1996 Two-phase coexistence in Fe–Ni alloys synthesized by ball milling J. Appl. Phys. 79 3946–55
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.
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 ...
The effect of various milling parameters, like type of milling, ball-to-powder ratio, milling speed, and milling time, has been well documented ... A.W. Weeber and H. Bakker: Amorphization by ball milling. A review. Physica B 153, …
X-ray diffraction has been used to investigate the kinetics of amorphization through ball-milling at 20 Hz, for five zeolitic imidazolate frameworks (ZIFs) - ZIF-8, ZIF-4, ZIF-zni, BIF-1-Li and CdIF-1. We find that the rates of amorphization for the …
Thanks also to Molly Black for her assistance with the Freezemobile 12 freeze dryer and the Averback-Bellon research groups in the Department of Materials Science and Engineering at the University of Illinois at Urbana-Champaign for their help with the …
Upon facile amorphisation by ball milling, the guest retention is greatly enhanced. Abstract The I 2 -sorption and -retention properties of several existing zeolitic imidazolate frameworks (ZIF-4, -8, -69) and a novel framework, ZIF-mnIm ([Zn(mnIm) 2 ]; mnIm=4-methyl-5-nitroimidazolate), have been characterised using microanalysis ...
For preparations involving ball milling, hydantoin 3 (1 mg) and BLG (50 mg) were ball-milled at 30 Hz for 10 min, with a mixer mill (MM 400, Retsch, Germany) using 1.5 mL stainless-steel jars (with 20 stainless-steel balls, 3 mm Ø; m ball =0.033 g each, m tot =0.65 g). After milling, the resulting powder was treated as described above for the ...
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.
A proposed microstructural mechanism is shown in fig. S6. Similar phenomenon has been observed in extreme deformation of brittle materials (23–27) and takes place during processes such as ball milling . The versatility and synergy of deformation mechanisms in HEAs render them as viable candidates for extreme load-bearing applications such as ...
It has been reported that the impact energy of HEBM is typically 1000 times higher than the conventional ball milling energy. 43 The major use of the conventional ball milling is to fracture the particles and to reduce the size, while in high energy ball milling, a longer milling time can be achieved, which can help to activate and complete the ...
In this way the amorphization process by ball-milling can be seen as a continuous increase in the volume fraction of zones with local disorder of the crystallographic structures.
Abstract In this study, the putative correlation between the molecular mobility of a polymer and the ball milling drug amorphization kinetics (i.e., time to reach full drug amorphization, ta) was studied using different grades of dextran (Dex) and polyvinylpyrrolidone (PVP) and the two model drugs indomethacin (IND) and chloramphenicol (CAP).
The dry milling of the ZrO 2-CeO 2 mixture powders was performed using a high-energy planetary ball mill system at a rotation speed of 250 rpm. The milling time varied from 1 to 150 h. The milling process was stopped for an interval of 15 min per hour for the purpose of lowering the milling temperature. The ball-to-powder weight ratio is 15:1.
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 …
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
Amorphization by mechanical milling (MM), where a single composition (e.g. intermetallic compound) is milled requires the accumulation of defects to induce the transformation. It is concluded that anti-site chemical disorder and nanocrystalline grain boundaries are the important defects in this regard.
In this study, the putative correlation between the molecular mobility of a polymer and the ball milling drug amorphization kinetics (i.e., time to reach full drug amorphization, ta) was studied using different grades of dextran (Dex) and polyvinylpyrrolidone (PVP) and the two model drugs indomethacin (IND) and chloramphenicol (CAP). In general, IND had lower ta …
Objectives: The purposes of this study were to clarify the amorphization by ball milling of atorvastatin calcium sesquihydrate (AT) and to analyse the change in dissolution kinetics. Methods: The amorphous AT was prepared from crystal AT by ball milling and analysed in terms of the changes of its physicochemical properties by powder X-ray diffraction analysis (XRD), …
alongside a 10 mm stainless steel milling ball at room temperature and sealed properly. This combination was then subjected to 30 Hz milling in a Retsch MM400 grinder mill for varying times. After milling, the amorphous milling products were recovered and characterized. SI-2: Ball-milling Amorphization
