scholarly journals Role of Sn as a Process Control Agent on Mechanical Alloying Behavior of Nanocrystalline Titanium Based Powders

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2110
Author(s):  
Izabela Matuła ◽  
Maciej Zubko ◽  
Grzegorz Dercz
Keyword(s):  
Process Control ◽  
Mechanical Alloying ◽  
Control Agent ◽  
Milling Process ◽  
Nanocrystalline Phase ◽  
X Ray Diffraction ◽  
Process Control Agent ◽  
Backscattered Electrons ◽  
Nanocrystalline Titanium

In this study, the effects of Sn as a process control agent (PCA) on the final powder sizes, morphology, homogenization and alloying process of a new titanium alloy were investigated. Two kinds of powders, Ti10Ta8Mo and Ti10Ta8Mo3Sn (wt %), were prepared using a mechanical alloying process. For the Ti10Ta8Mo3Sn (wt %) alloy, the Sn element was used as PCA to enhance the milling process in the planetary ball mill. The milling process of both compositions was carried out with 200 rpm for 10, 15, 20, 40, 60, 80 and 100 h. The results confirmed that using Sn as a process control agent can result in a relatively good size distribution and better yield performance compared to samples without Sn addition. The phase analysis using X-ray diffraction proved the formation of the α nanocrystalline phase and the partial phase transformation from α to nanocrystalline β phases of both alloy compositions. The Scaning Electron Micoscope- Backscattered Electrons SEM-BSE results confirmed that the use of Sn as the PCA can provide a better homogenization of samples prepared by at least 60 h of ball milling. Furthermore, the presence of Sn yielded the most uniform, spheroidal and finest particles after the longest milling time.

SYNTHESIS OF NANO-CRYSTALLINE Cu-Cr ALLOY BY MECHANICAL ALLOYING

2012 ◽  
Vol 05 ◽  
pp. 496-501 ◽  
Author(s):  
S. SHEIBANI ◽  
S. HESHMATI-MANESH ◽  
A. ATAIE
Keyword(s):  
Mechanical Alloying ◽  
Structural Evolution ◽  
High Energy ◽  
Lattice Parameter ◽  
Control Agent ◽  
Milling Process ◽  
X Ray Diffraction ◽  
Nano Crystalline ◽  
High Energy Ball Mill ◽  
Energy Ball

In this paper, the influence of toluene as the process control agent (PCA) and pre-milling on the extension of solid solubility of 7 wt.% Cr in Cu by mechanical alloying in a high energy ball mill was investigated. The structural evolution and microstructure were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques, respectively. The solid solution formation at different conditions was analyzed by copper lattice parameter change during the milling process. It was found that both the presence of PCA and pre-milling of Cr powder lead to faster dissolution of Cr . The mean crystallite size was also calculated and showed to be about 10 nm after 80 hours of milling.

ROLE OF PROCESS CONTROL AGENT ON MECHANICAL ALLOYING OF NANO STRUCTURED TiAl-BASED ALLOY

2008 ◽  
Vol 22 (18n19) ◽  
pp. 2933-2938 ◽  
Author(s):  
H. BAHMANPOUR ◽  
S. HESHMATI-MANESH
Keyword(s):  
Process Control ◽  
Stearic Acid ◽  
Milled Powder ◽  
High Energy ◽  
Control Agent ◽  
X Ray Diffraction ◽  
Process Control Agent ◽  
Crystallite Sizes ◽  
Energy Ball ◽  
Milled Powders

High energy ball milling was performed on a mixture of titanium and aluminum elemental powders with a composition of Ti -48(at.%) Al . Stearic acid was added to this powder mixture as a process control agent (PCA) to study its effect on the microstructure evolution and crystallite size of the milled powder after various milling times. Phase compositions and morphology of the milled powders were evaluated using X-ray diffraction and scanning electron microscopy. Crystallite sizes of milled powders were determined by Cauchy-Gaussian approach using XRD profiles. It was shown that addition of 1wt.% of stearic acid not only minimizes the adhesion of milling product to the vial and balls, but also reduces its crystallite sizes. It has also a marked effect on the morphology of the final product.

Combustion Synthesis of Mechanically-Activated Nb-Al Mixtures

2005 ◽  
Vol 498-499 ◽  
pp. 152-157 ◽  
Author(s):  
Fabiana Buracovas ◽  
Valéria S. Gonçalves ◽  
Cláudio José da Rocha ◽  
Ricardo Mendes Leal Neto
Keyword(s):  
Water Immersion ◽  
Control Agent ◽  
Milling Process ◽  
Sem Analysis ◽  
X Ray Diffraction ◽  
Process Control Agent ◽  
Effective Dispersion ◽  
Powder Mass ◽  
Ignition And Combustion ◽  
Milled Powders

In this work shake milling were used to mechanically activate Nb – Al powder mixtures at different relative proportions (Nb80Al, Nb65Al, Nb54Al e Nb42Al). All milling process parameters were unchanged, e.g., powders mass, ball/powder mass ratio, balls diameter, quantity and kind of process control agent. Uniaxially compacted cylindrical pellets of milled powders were vacuum reacted. After a two-step degassing treatment (290°C for 0.5 h and 400°C for 4 h), samples were heated at 30°C/min. Ignition and combustion temperatures were measured by a thermocouple inserted in a hole drilled into the pellets. The microstructure of milled powders and reacted pellets were characterized by X-ray diffraction and SEM analysis. Bulk density of the pellets was measured by water immersion (Archimedes). The results showed a decrease of both ignition and combustion temperature with mechanical activation as seen by comparison with reacted pellets of the same composition not mechanically activated (simple mixtures). By increasing the heating hate the completeness of the reactions were improved. The lower the aluminum contents the lower the ignition and combustion temperatures and also the densification. The decrease on ignition temperature was caused by a more effective dispersion (and so more activation) attained by samples with lower aluminum content.

scholarly journals Effects of Process Control Agent Amount, Milling Time, and Annealing Heat Treatment on the Microstructure of AlCrCuFeNi High-Entropy Alloy Synthesized through Mechanical Alloying

Metals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1493
Author(s):  
Negar Yazdani ◽  
Mohammad Toroghinejad ◽  
Ali Shabani ◽  
Pasquale Cavaliere
Keyword(s):  
Solid Solution ◽  
Process Control ◽  
Mechanical Alloying ◽  
Milling Time ◽  
Control Agent ◽  
High Entropy Alloy ◽  
Process Control Agent ◽  
Mechanically Alloyed ◽  
X Ray ◽  
High Entropy

This study was conducted to investigate the characteristics of the AlCrCuFeNi high-entropy alloy (HEA) synthesized through mechanical alloying (MA). In addition, effects of Process Control Agent (PCA) amount and milling time were investigated using X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS). The results indicated that the synthesized AlCrCuFeNi alloy is a dual phase (FCC + BCC) HEA and the formation of the phases is strongly affected by the PCA amount. A high amount of PCA postponed the alloying process and prevented solid solution formation. Furthermore, with an increase in the PCA amount, lattice strain decreased, crystallite size increased, and the morphology of the mechanically alloyed particles changed from spherical to a plate-like shape. Additionally, investigation of thermal properties and annealing behavior at different temperatures revealed no phase transformation up to 400 °C; however, the amount of the phases changed. By increasing the temperature to 600 °C, a sigma phase (σ) and a B2-ordered solid solution formed; moreover, at 800 °C, the FCC phase decomposed into two different FCC phases.

Preparation of Nanocrystalline Ba-Cu-Si Clathrate Powders by Mechanical Milling Using a Process Control Agent

2014 ◽  
Vol 29 ◽  
pp. 121-127 ◽  
Author(s):  
A. Zolriasatein ◽  
Xin Lin Yan ◽  
P. Rogl ◽  
A. Shokuhfar ◽  
S. Paschen
Keyword(s):  
Electron Microscopy ◽  
Process Control ◽  
Mechanical Milling ◽  
Control Agent ◽  
X Ray Diffraction ◽  
Process Control Agent ◽  
X Ray ◽  
Particle Size And Morphology ◽  
Size And Morphology ◽  
Scanning Electron

Nanostructured Ba-Cu-Si clathrate powders were synthesized by mechanical milling using different amounts of process control agent (PCA). We investigated systematically the effects of PCA on the phase constitution and crystallite size of nanopowders using X-ray diffraction (XRD) as well as the particle size and morphology by scanning electron microscopy (SEM). The PCA increases the powder yield by reducing the powder agglomeration. No detectable reaction occurred between the PCA and the clathrate phase, and thus the composition of the clathrate phase is unchanged after milling. Compared to the powders milled without PCA, the crystalline size of powders with PCA is reduced from about 70 to about 50 nm.

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