Influence of Mechanical Activation and Mechanical Alloying on the Structure, Phase State of the Fe-Ni-Co-Al-Nb Powder Composition and on High-Entropy Coatings Based on it

2021 ◽  
Vol 1037 ◽  
pp. 494-502
Author(s):  
Zhesfina Michailovna Blednova ◽  
Etibar Yusif O. Balaev ◽  
Anna Pavlovna Yurkova
Keyword(s):  
Mechanical Alloying ◽  
Mechanical Activation ◽  
Phase State ◽  
Alloying Effect ◽  
Workpiece Surface ◽  
High Entropy ◽  
Powder Composition ◽  
Assessment Study ◽  
Structure Phase

The article presents the assessment study of mechanical activation and mechanical alloying effect on the structure, phase state of the powder composition and of the coating based on it. The duration of mechanical activation was varied as follows: 1 h, 2 h, 4 h, 8 h, 16 h, 32 h. It is shown that in order to from a high-entropy FeNiCoAlNb alloy on the workpiece surface the duration of mechanical activation must be at least 4 hours. We described the mechanism of mechanical alloying and ways of accelerating this process.

scholarly journals Influence of V and Heat Treatment on Characteristics of WMoNbTaV Refractory High-Entropy Alloy Coatings by Mechanical Alloying

Coatings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 265
Author(s):  
Chun-Liang Chen ◽  
Sutrisna
Keyword(s):  
Heat Treatment ◽  
Mechanical Alloying ◽  
Annealing Treatment ◽  
High Energy ◽  
304 Stainless Steel ◽  
Homogeneous Distribution ◽  
High Entropy Alloy ◽  
Solid Solution Phase ◽  
High Entropy ◽  
Steel Substrates

Refractory high-entropy alloy (RHEA) is one of the most promising materials for use in high-temperature structural materials. In this study, the WMoNbTaV coatings on 304 stainless steel substrates has been prepared by mechanical alloying (MA). Effects of V addition and subsequent heat treatment on properties of the WMoNbTaV coatings were investigated. The results show that the RHEA coatings with nanocrystalline body-centered cubic (BCC) solid-solution phase were generated by the mechanical alloying process. The presence of the V element promotes a uniform microstructure and homogeneous distribution of composition in the RHEA coatings due to improving alloying efficiency, resulting in an increase of hardness. After the annealing treatment of the RHEA coatings, microstructure homogeneity was further enhanced; however, the high affinity of Ta for oxygen causes the formation of Ta-rich oxides. Annealing also removes strain hardening generated by high-energy ball milling and thus decreases the hardness of the RHEA coating and alters microstructure evolution and mechanical properties.

Solidification and the Structure-Phase State of Ni3Al–Ni–NiAl Alloys with Chromium, Molybdenum, Tungsten, Rhenium, and Cobalt

2020 ◽  
Vol 2020 (5) ◽  
pp. 540-548
Author(s):  
K. B. Povarova ◽  
A. A. Drozdov ◽  
O. A. Bazyleva ◽  
M. A. Bulakhtina ◽  
A. E. Morozov ◽  
...  
Keyword(s):  
Phase State ◽  
Structure Phase

scholarly journals Structure-Phase Transformations in the Course of Solid-State Mechanical Alloying of High-Nitrogen Chromium-Manganese Steels

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 301
Author(s):  
Kirill Lyashkov ◽  
Valery Shabashov ◽  
Andrey Zamatovskii ◽  
Kirill Kozlov ◽  
Natalya Kataeva ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Solid State ◽  
Mechanical Alloying ◽  
Ball Milling ◽  
Ball Mill ◽  
Subsequent Annealing ◽  
High Nitrogen ◽  
Transmission Electron ◽  
Structure Phase ◽  
Manganese Steels

The solid-state mechanical alloying (MA) of high-nitrogen chromium-manganese austenite steel—MA in a planetary ball mill, —was studied by methods of Mössbauer spectroscopy and transmission electron microscopy (TEM). In the capacity of a material for the alloying we used mixtures of the binary Fe–Mn and Fe–Cr alloys with the nitrides CrN (Cr2N) and Mn2N. It is shown that ball milling of the mixtures has led to the occurrence of the α → γ transitions being accompanied by the (i) formation of the solid solutions supersaturated with nitrogen and by (ii) their decomposition with the formation of secondary nitrides. The austenite formed by the ball milling and subsequent annealing at 700–800 °C, was a submicrocrystalline one that contained secondary nano-sized crystalline CrN (Cr2N) nitrides. It has been established that using the nitride Mn2N as nitrogen-containing addition is more preferable for the formation and stabilization of austenite—in the course of the MA and subsequent annealing—because of the formation of the concentration-inhomogeneous regions of γ phase enriched with austenite-forming low-mobile manganese.

Superior Quality Rails: Structure-Phase States and Defect Substructure

2014 ◽  
Vol 1013 ◽  
pp. 127-132 ◽  
Author(s):  
Victor Gromov ◽  
Alexei Yuriev ◽  
Yurii F. Ivanov ◽  
Konstantin Morozov ◽  
Sergey Konovalov ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Phase State ◽  
Layer By Layer ◽  
Quantitative Parameters ◽  
Defect Substructure ◽  
Transmission Electron ◽  
Layer Analysis ◽  
Structure Phase

Using transmission electron microscopy methods the layer by layer analysis of the bulk hardened superior quality rails is carried out and the quantitative parameters of structure, phase state and defect substructure gradients are established. It is shown that the interface boundaries globular cementite particles-matrix are the possible places of microcracks initiation.

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