Synthesis of Nanocrystalline Tungsten Alloy by Mechanical Alloying and Annealing

2005 ◽  
Vol 23 ◽  
pp. 239-242 ◽  
Author(s):  
Z.G. Liu ◽  
L. Lu ◽  
M.O. Lai
Keyword(s):  
Mechanical Alloying ◽  
Structural Characterization ◽  
Amorphous Matrix ◽  
Amorphous Structure ◽  
Tungsten Alloy ◽  
Tungsten Alloys ◽  
Iron Powders ◽  
Nanocrystalline Phases

Formation of partial nanocrystal and amorphous tungsten alloys was synthesized via crystallization of a completely amorphized tungsten alloy synthesized by mechanical alloying. Structural characterization shows formation of amorphous structure from mechanical alloying of a mixture of elemental tungsten and iron powders after about 150 hours. Partial nanocrystalline phases within the amorphous matrix were formed through annealing the amorphous tungsten alloy at 1075°C.

Influence of Cu Substitution on the Structure and Magnetic Properties of Partially Crystallized Fe62-xCo10Y8MexB20 Alloys

2017 ◽  
Vol 68 (2) ◽  
pp. 408-410 ◽  
Author(s):  
Konrad Gruszka ◽  
Marcin Nabialek ◽  
Michal Szota
Keyword(s):  
Magnetic Properties ◽  
Amorphous Matrix ◽  
Cell Structure ◽  
Amorphous Structure ◽  
Thin Plates ◽  
One Step ◽  
Partial Crystallization ◽  
The One ◽  
Nanocrystalline Phases ◽  
Composition Changes

The paper presents results of structural and magnetic properties investigation of partially crystallized Fe62Co10Y8B20 and Fe61Co10Y8Cu1B20 alloys. Multicomponent bulk amorphous alloys exhibit a significant sensitivity to the composition changes. Even a small quantitative element substitution in composition of the initial alloy may lead to substantial changes in its various properties. Samples in form of thin plates were obtained by radial cooling method resulting in a complete amorphous structure material. Then, the one-step controlled heat treatment process led to partial crystallization of the sample causing the coexistence of amorphous matrix and embedded nanocrystalline phases. As shown in article, amorphous matrix has a noticeable influence on nano-sized grains resulting in a deformation of primary cell structure. Isothermal annealing process also had an impact on the magnetic properties of obtained samples, which was examined by the vibrating sample magnetometer (VSM).

scholarly journals Comparative Assessment of Tungsten Toxicity in the Absence or Presence of Other Metals

Toxics ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 66 ◽  
Author(s):  
Ola Wasel ◽  
Jennifer Freeman
Keyword(s):  
Human Exposure ◽  
Potable Water ◽  
Comparative Assessment ◽  
Tungsten Alloy ◽  
Tungsten Alloys ◽  
Mechanisms Of Toxicity ◽  
Adverse Health Effects ◽  
Current State ◽  
Wide Range ◽  
Military Applications

Tungsten is a refractory metal that is used in a wide range of applications. It was initially perceived that tungsten was immobile in the environment, supporting tungsten as an alternative for lead and uranium in munition and military applications. Recent studies report movement and detection of tungsten in soil and potable water sources, increasing the risk of human exposure. In addition, experimental research studies observed adverse health effects associated with exposure to tungsten alloys, raising concerns on tungsten toxicity with questions surrounding the safety of exposure to tungsten alone or in mixtures with other metals. Tungsten is commonly used as an alloy with nickel and cobalt in many applications to adjust hardness and thermal and electrical conductivity. This review addresses the current state of knowledge in regard to the mechanisms of toxicity of tungsten in the absence or presence of other metals with a specific focus on mixtures containing nickel and cobalt, the most common components of tungsten alloy.

Thermal and structural characterization of Fe–Nb–B alloys prepared by mechanical alloying

2004 ◽  
Vol 375-377 ◽  
pp. 874-880 ◽  
Author(s):  
J.J. Suñol ◽  
A. González ◽  
J. Saurina ◽  
Ll. Escoda ◽  
P. Bruna
Keyword(s):  
Mechanical Alloying ◽  
Structural Characterization

Current status of ductile tungsten alloy development by mechanical alloying

2004 ◽  
Vol 329-333 ◽  
pp. 775-779 ◽  
Author(s):  
Y Ishijima ◽  
H Kurishita ◽  
K Yubuta ◽  
H Arakawa ◽  
M Hasegawa ◽  
...  
Keyword(s):  
Mechanical Alloying ◽  
Current Status ◽  
Tungsten Alloy ◽  
Alloy Development

scholarly journals Structural Characterization of Cu10Mo Alloy Synthesized by Mechanical Alloying

2018 ◽  
Vol 24 (S1) ◽  
pp. 800-801 ◽  
Author(s):  
O. Hernández ◽  
C. Aguilar ◽  
A. Medina ◽  
L. Béjar ◽  
C. Parra ◽  
...  
Keyword(s):  
Mechanical Alloying ◽  
Structural Characterization

Synthesis of nanocrystalline copper–tungsten alloys by mechanical alloying

2001 ◽  
Vol 304-306 ◽  
pp. 438-441 ◽  
Author(s):  
T. Raghu ◽  
R. Sundaresan ◽  
P. Ramakrishnan ◽  
T.R. Rama Mohan
Keyword(s):  
Mechanical Alloying ◽  
Nanocrystalline Copper ◽  
Tungsten Alloys

New Ni-Me-P Electrode Materials

2015 ◽  
Vol 228 ◽  
pp. 39-48
Author(s):  
Bożena Łosiewicz ◽  
Magdalena Popczyk ◽  
Patrycja Osak
Keyword(s):  
Electrode Materials ◽  
Amorphous Matrix ◽  
Alloy Coating ◽  
Amorphous Structure ◽  
Deposition Potential ◽  
Nickel Matrix ◽  
Surface Distribution ◽  
Molecular Mixing ◽  
X Ray

The Ni-Me-P alloy coatings containing metal as alloying component (Me = Co, W) in a Ni-P amorphous matrix, were potentiostatically electrodeposited onto a polycrystalline Cu substrate. Deposition potential was established based on polarization curves of electrodeposition of Ni-Co-P, Ni-W-P and Ni-P alloy coatings. SEM, EDS, XRD and X-ray microanalysis methods, were applied for chemical and physical characterization of the obtained coatings. Linear analysis of Ni, Co and W distribution in the microregions of the appropriate alloy coating revealed that surface distribution of these elements is homogeneous what is due to a molecular mixing of the amorphous nickel matrix with the alloying components. It was found that the Ni-Co-P and Ni-W-P coatings have the amorphous structure like the Ni-P deposit and alloying components as Co or W are built-in into the appropriate coating in the amorphous form. The mechanism of the induced codeposition of these ternary Ni-Me-P coatings, has been discussed.

Study on Cu48Zr43Al9 and Cu54Zr40Al6 Amorphous Matrix Alloys by Mechanical Spectroscopy

2015 ◽  
Vol 365 ◽  
pp. 317-322
Author(s):  
Odila Florêncio ◽  
Paulo Wilmar Barbosa Marques ◽  
Paulo Sergio Silva ◽  
Javier Andres Muñoz Chaves ◽  
L.C. Rodriguez Aliaga ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Internal Friction ◽  
Amorphous Matrix ◽  
Glassy State ◽  
Flexural Vibration ◽  
Amorphous Structure ◽  
Mechanical Relaxation ◽  
Nominal Composition ◽  
Mechanical Spectroscopy ◽  
Casting Technique

Anelastic properties of Bulk Metallic Glasses (BMG) were studied by mechanical spectroscopy using a flexural vibration apparatus. BMG’s samples, with nominal composition Cu48Zr43Al9and Cu54Zr40Al6, were produced by skull push-pull casting technique in rectangular cavity cooper mold. In both samples, the differential scanning calorimeter patterns have evidenced the presence of amorphous structure, although the X-ray diffraction for Cu48Zr43Al9composition has shown a heterogeneous microstructure embedded in the amorphous matrix. Anelastic relaxation spectra were obtained using an acoustic elastometer system with vibration frequency in the kilohertz bandwidth, a heating rate of 1 K/min, vacuum greater than 10-5mBar in the temperature range of 300 K to 620 K. In the flexural apparatus, an acoustic elastometer system, the internal friction (energy loss) and the elastic modulus were obtained by free decay of vibrations and by the squared of the oscilation frequency, respectively. Internal friction spectra were not reproducible among the measurements, which may imply atomic rearrangement in the samples due to consecutive heating. Normalized elastic modulus data showed distinct behavior from the first to the other measurements evidencing irreversible microstructural alterations in the samples possibly associated with mechanical relaxation due to the motion of atoms or clusters in the glassy state.

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