Study on Preparation of the Core-Nanoshell Composite Absorbers by High-Energy Ball Milling at Room Temperature

2012 ◽  
Vol 12 (2) ◽  
pp. 1594-1598 ◽  
Author(s):  
Ruxin Che ◽  
Hong Gao ◽  
Bing Yu ◽  
Shuo Wang ◽  
Chunxia Wang
Keyword(s):  
Ball Milling ◽  
Room Temperature ◽  
High Energy ◽  
High Energy Ball Milling ◽  
The Core ◽  
Energy Ball

Synchrotron X-ray Absorption Studies of Atomic-Level Alloying in Immiscible Mixtures

1998 ◽  
Vol 524 ◽  
Author(s):  
J.-H. He ◽  
P. J. Schilling ◽  
E. Ma
Keyword(s):  
Ball Milling ◽  
Room Temperature ◽  
High Energy ◽  
Atomic Level ◽  
High Energy Ball Milling ◽  
Edge Structure ◽  
X Ray ◽  
Energy Ball ◽  
Immiscible Mixtures ◽  
X Ray Absorption

ABSTRACTAn X-ray absorption beamline has been developed recently at the electron storage ring of the LSU Center for Advanced Microstructures and Devices. Using Extended X-ray Absorption Fine Structure (EXAFS) and X-ray Absorption Near Edge Structure (XANES), we have studied the local atomic environments in immiscible mixtures processed by high-energy ball milling, a mechanical alloying technique involving heavy deformation. By examining the local coordination and bond distances, it is concluded that atomic-level alloying can indeed be induced between Cu and Fe through milling at room temperature, forming substitutional fcc and bcc solid solutions. In addition to single-phase regions, a two-phase region consisting of fcc/bcc solutions has been found after milling at both room temperature and liquid nitrogen temperature. In contrast to the Cu-Fe system, solid solution formation is not detectable in milled Ag-Fe and Cu-Ta mixtures. This work demonstrates the power of synchrotron EXAFS/XANES experiments in monitoring nonequilibrium alloying on the atomic level. At the same time, the results provide direct experimental evidence of the capability as well as limitations of high-energy ball milling to form alloys in positive-heat-of-mixing systems.

Mechanical Alloying of Pet and Pet/Vectra Blends

1996 ◽  
Vol 461 ◽  
Author(s):  
C. M. Balik ◽  
C Bai ◽  
C.C Koch ◽  
R.J Spontak ◽  
C. K. Saw
Keyword(s):  
Molecular Weight ◽  
Mechanical Alloying ◽  
Ball Milling ◽  
Liquid Nitrogen ◽  
Room Temperature ◽  
Potential Method ◽  
High Energy ◽  
High Energy Ball Milling ◽  
Weight Density ◽  
Energy Ball

ABSTRACTMechanical alloying represents a potential method for producing finely dispersed alloys of normally incompatible polymers. In this paper, PET and blends of PET with a Vectra thermotropic copolyester have been processed via high energy ball milling at room temperature (ambimilled) and at liquid nitrogen temperatures (cryomilled). Milled powders and compacted disks have been characterized using molecular weight, density and hardness measurements, aswell as DSC, WAXS, TEM and FTIR.

Structural transformations of alumina by high energy ball milling

1993 ◽  
Vol 8 (11) ◽  
pp. 2985-2992 ◽  
Author(s):  
P.A. ZielińAski ◽  
R. Schulz ◽  
S. Kaliaguine ◽  
A. Van Neste
Keyword(s):  
Heat Treatment ◽  
High Temperature ◽  
Ball Milling ◽  
Room Temperature ◽  
High Energy ◽  
Structural Transformations ◽  
High Energy Ball Milling ◽  
Second Step ◽  
Transformation Rate ◽  
Energy Ball

Room temperature, high energy ball milling was applied to various transition aluminas (γ, K, χ), producing thermodynamically stable α-alumina–a phenomenon that could otherwise be achieved only by high temperature (1100–1200 °C) heat treatment. The transformation proceeds in two steps. The first one consists of rapid microstructural rearrangements with continuously increasing α-transformation rate. In the second step (1–2 h from the start), only relatively small changes in morphology are observed with a constant α-transformation rate. The rate is influenced only by the milling intensity. The presence or the absence of oxygen in the milling atmosphere has a large influence on the final surface area of α-alumina.

Room temperature hydrogen absorption by Mg and Mg TiFe nanocomposites processed by high-energy ball milling

2018 ◽  
Vol 43 (27) ◽  
pp. 12251-12259 ◽  
Author(s):  
R.A. Silva ◽  
R.M. Leal Neto ◽  
D.R. Leiva ◽  
T.T. Ishikawa ◽  
C.S. Kiminami ◽  
...  
Keyword(s):  
Ball Milling ◽  
Hydrogen Absorption ◽  
Room Temperature ◽  
High Energy ◽  
High Energy Ball Milling ◽  
Energy Ball

Microstructures and Mechanical Properties of TiAl-Based Alloys Prepared by High-Energy Ball Milling and Hot-Pressing Sintering

2011 ◽  
Vol 704-705 ◽  
pp. 828-831
Author(s):  
Tian Guo Wang ◽  
Qun Qin ◽  
Qiu Yue Shi ◽  
Wen Jun Zhang
Keyword(s):  
Mechanical Properties ◽  
Ball Milling ◽  
Hot Pressing ◽  
Room Temperature ◽  
High Energy ◽  
High Energy Ball Milling ◽  
Uniform Microstructure ◽  
Energy Ball ◽  
Hot Pressing Sintering ◽  
The Relationship

TiAl-based alloy with a composition of Ti-47%Al-3%Cr (mole fraction) was prepared by high-energy ball milling and hot-pressing sintering. The relationship between microstructure and mechanical properties of Ti-47%Al-3%Cr alloy was studied by X-ray diffractometry (XRD), scanning electron microscopy (SEM) and mechanical testing. The results showed that the TiAl-based alloy with high density and uniform microstructure could be obtained by high-energy ball milling and hot-pressing sintering. The compactibility and sintering densification of the element powder could be promoted efficiently by high-energy ball milling. The main phase TiAl and few phases Ti3Al were observed in the hot pressing sintering bulk samples. In addition, the microstructure changed with ball milling times, as a result, the mechanical properties changed with the microstructure. The finer the microstructure was, the higher the strength at room temperature became. After the element powder was milled for 20 hours and hot-pressing sintered at 1300 °C for 2 hours, TiAl-based alloys were found to have good room temperature mechanical properties with the compressive strength of 2870 Mpa and the relative compressive ratio of 27.3%. Keywords: TiAl-based alloys; hot-pressing sintering; microstructure; mechanical properties

scholarly journals Evidence for self-sustained MoSi2 formation during room-temperature high-energy ball milling of elemental powders

1993 ◽  
Vol 8 (8) ◽  
pp. 1836-1844 ◽  
Author(s):  
E. Ma ◽  
J. Pagán ◽  
G. Cranford ◽  
M. Atzmon
Keyword(s):  
Ball Milling ◽  
Room Temperature ◽  
High Energy ◽  
High Energy Ball Milling ◽  
Diffusion Couples ◽  
Compound Formation ◽  
Fine Grained ◽  
Energy Ball ◽  
High Temperature Reactions ◽  
Thin Film Diffusion

We present evidence indicating that rapid, self-sustained, high-temperature reactions play an important role in the formation of tetragonal MoSi2 during room-temperature high-energy ball milling of elemental powders. Such reactions appear to be ignited by mechanical impact in an intimate, fine-grained, Mo–Si physical mixture formed after an initial milling period. Under certain conditions, limited propagation of self-sustained reactions in these uncompacted powder mixtures renders the compound formation seemingly gradual in bulk-averaged analysis. It is suggested that this type of reaction is an important mechanism in the mechanical alloying of highly exothermic systems. Results are discussed in comparison with similar reactions we observed in ball-milled Al–Ni powders, with self-sustained combustion synthesis previously reported for Mo–Si powders, and with interfacial diffusional reactions in Mo–Si powders or thin-film diffusion couples.

Temperature Dependence of Magnetic Properties in Ferrite Powders by High Energy Ball Milling

2014 ◽  
Vol 804 ◽  
pp. 153-156
Author(s):  
Chan Seok Hong ◽  
Yo Seung Song ◽  
Si Young Chang
Keyword(s):  
Ball Milling ◽  
Room Temperature ◽  
Sintered Sample ◽  
High Energy ◽  
Initial Permeability ◽  
High Energy Ball Milling ◽  
Nanosized Particles ◽  
Mean Size ◽  
Energy Ball ◽  
Increasing Temperature

The ferrite powders were prepared by high energy ball-milling, and subsequently compacted under a pressure of 490MPa for 3min and sintered at 1273~1673K for 3h. The spherical shaped initial powders with a mean size of approximately 70μm were changed to irregular shaped powders of 230nm in a mean size after milling at 300rpm for 3h. The milled powders were composed of the nanosized particles with a size of approximately 10nm. After compacting, the green density was approximately 70%. The sintered sample with a relative density of approximately 98% was obtained by sintering at 1473K, which showed the saturation magnetization (Ms) of approximately 90emu/g and the coercivtity (Hc) of approximately 19Oe at room temperature. The Ms decreased with increasing temperature, whereas the Hc and initial permeability (μi) were unchanged. There was no change in the Ms, Hc and μi during holding at 423K.

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