High-Energy Ball-Milling of FeAl2 and Fe2Al5 Intermetallic Systems

2013 ◽  
Vol 755 ◽  
pp. 47-52 ◽  
Author(s):  
J.R. Romero-Romero ◽  
J. Luis López-Miranda ◽  
R. Esparza ◽  
M.A. Espinosa-Medina ◽  
G. Rosas

In this study, FeAl2 and Fe2Al5 intermetallic alloys were prepared by conventional casting technique. In order to study their structural stability the alloys were subjected to high-energy ball milling process for 1, 2.5, 5 and 10 h. The structural and chemical characterizations were conducted by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and differential scanning calorimetry. After 10 h of milling, the experimental results indicated a phase transformation from FeAl2-triclinic phase to Fe2Al5-ortorrombic structure. This phase transformation is characterized by a change from low to high symmetry systems.

2016 ◽  
Vol 40 ◽  
pp. 174-179 ◽  
Author(s):  
Hua Lin ◽  
Li Zhao Qin ◽  
He Hong ◽  
Qing Li

Nano-sized starch particles were prepared from potato starch via high-energy ball milling, which is a purely physical method. Scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, differential scanning calorimetry, and viscometer were used to analyze the morphology and characteristics of the as-prepared nanoparticles. Spherical particles with an average size of approximately 120 nm were obtained after grinding the samples for 90 min, and the particles were free from any contamination. The particle surface was rough with a plush-like feature, and the adsorption ability was six times higher than that of native starch. Thus, the nano-sized starch particles can be used as a good embedding medium in biomedical and chemical materials.


2013 ◽  
Vol 755 ◽  
pp. 133-138 ◽  
Author(s):  
J. Luis López-Miranda ◽  
J.R. Romero-Romero ◽  
R. Esparza ◽  
G. Rosas

In this work, we reported the results obtained by the structural characterization of the FeAl3 intermetallic compound. This material was synthesized by conventional casting technique using Fe (99.97%) and Al (99.92%) elemental metals. Then, the as-cast alloy was subjected to high-energy ball-milling for different times (1, 2.5, 5, 7.5, 10 and 15 h). The characterization of the alloy was performed by X-ray diffraction patterns, scanning and transmission electron microscopy. The results show that FeAl3 intermetallic was produced as a single-phase after conventional casting. The milled experiments show that the FeAl3 (monoclinic) transforms to Fe2Al5 (orthorhombic) after 15h of milling. Therefore, this phase transformation is characterized by a change from low to high symmetry systems.


2003 ◽  
Vol 775 ◽  
Author(s):  
J. Eric Hampsey ◽  
Claudio L. De Castro ◽  
Byron F. McCaughey ◽  
Donghai Wang ◽  
Brian S. Mitchell ◽  
...  

AbstractHighly ordered mesoporous silica particles with sizes in the micron to sub-micron range are of great interest due to their applications as catalysts and filler materials. Currently, mesoporous silica particles are synthesized using large amounts of solvent, which is impractical for large scale-up in industry. This paper reports on a high-energy ball milling process that has been employed to create micron to sub-micron sized mesoporous silica particles starting from a silica xerogel prepared by a surfactant self-assembly sol-gel process. We have studied the effect of parameters such as milling media (e.g., zirconia, stainless steel, and steel centered nylon balls), milling time, the presence of surfactants during milling, particle size, and pore structure. Results from transmission electron microscopy (TEM), scanning electron microscopy (SEM), Xray diffraction (XRD), and nitrogen adsorption demonstrate the feasibility of producing large quantities of mesostructured particles by a simple milling process.


Metals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1908
Author(s):  
Tomasz Goryczka ◽  
Piotr Salwa

A high-energy ball milling technique was used for production of the equiatomic NiTi alloy. The grinding batch was prepared in two quantities of 10 and 20 g. The alloy was produced using various grinding times. Scanning electron microscopy, X-ray diffraction, hardness measurement and differential scanning calorimetry were used for materials characterization at various milling stages. The produced alloy was studied by means of microstructure, chemical and phase composition, average grain and crystallite size, crystal lattice parameters and microstrains. Increasing the batch mass to 20 g and extending the grinding time to 140 h caused the increase in the average size of the agglomerates to 700 µm while the average crystallites size was reduced to a few nanometers. Microstrains were also reduced following elongation of milling time. Moreover, when the grinding time is extended, the amount of the monoclinic phase increases at the expense of the body-centered cubic one—precursors of crystalline, the B2 parent phase and the B19′ martensite. Crystallization takes place as a multistage process, however, at temperatures below 600 °C. After crystallization, the reversible martensitic transformation occurred with the highest enthalpy value—4 or 5 J/g after 120 and 140 h milling, respectively.


2006 ◽  
Vol 54 (1) ◽  
pp. 93-97 ◽  
Author(s):  
J.L. Li ◽  
L.J. Wang ◽  
G.Z. Bai ◽  
W. Jiang

2013 ◽  
Vol 745-746 ◽  
pp. 281-285
Author(s):  
Y.B. Yuan ◽  
Rui Xiao Zheng ◽  
Su Jing Ge ◽  
Han Yang ◽  
Chao Li Ma

Al86Ni7Y4.5Co1La1.5 (at.%) alloy powder was produced by argon gas atomization process. After high-energy ball milling, the powder was consolidated and extruded by using vacuum hot press sintering under different process conditions, sintering temperature, extrusion pressure, sintering time, etc.. The microstructure and morphology of the powder and consolidated bulk alloy were examined by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The phase transformation of the powder was investigated by differential scanning calorimetry (DSC). Mechanical properties of the consolidated bulk alloy were examined. The results showed that as the milling time increase, the volume fraction of amorphous materials and the hardness and yield strength of the bulk alloy were obvious improved.


2001 ◽  
Vol 16 (6) ◽  
pp. 1636-1643 ◽  
Author(s):  
L. B. Kong ◽  
J. Ma ◽  
T. S. Zhang ◽  
W. Zhu ◽  
O. K. Tan

Partially reacted mixtures of Pb(ZrxTi1−x)O3 and its corresponding starting oxide components were obtained by a high-energy ball milling process. The partially reacted powders were characterized by x-ray diffraction and scanning electron microscopy techniques. The sintering behavior of the milled mixtures has demonstrated a distinct volumetric expansion before the densification of the samples, which clearly shows the occurrence of a reactive sintering process of the partially reacted powders. Such process requires a lower densification temperature as compared with the PZT powders produced by the conventional solid-state reaction process. PZT ceramics were found to form directly from the partially reacted powders sintered at 900–1200 °C. The dielectric and ferroelectric properties of the PZT ceramics as a function of sintering temperature and milling time were also studied and discussed.


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