Grain boundary wetting by a solid phase; microstructural development in a Zn–5 wt% Al alloy

2004 ◽  
Vol 52 (15) ◽  
pp. 4537-4545 ◽  
Author(s):  
G.A López ◽  
E.J Mittemeijer ◽  
B.B Straumal
Keyword(s):  
Grain Boundary ◽  
Solid Phase ◽  
Microstructural Development ◽  
Al Alloy ◽  
Grain Boundary Wetting

Inversed solid-phase grain boundary wetting in the Al–Zn system

2011 ◽  
Vol 46 (12) ◽  
pp. 4349-4353 ◽  
Author(s):  
S. G. Protasova ◽  
O. A. Kogtenkova ◽  
B. B. Straumal ◽  
P. Zięba ◽  
B. Baretzky
Keyword(s):  
Grain Boundary ◽  
Solid Phase ◽  
Grain Boundary Wetting

Grain Boundary Wetting by a Second Solid Phase in the Zr-Nb Alloys

2012 ◽  
Vol 21 (5) ◽  
pp. 721-724 ◽  
Author(s):  
B. B. Straumal ◽  
A. S. Gornakova ◽  
Y. O. Kucheev ◽  
B. Baretzky ◽  
A. N. Nekrasov
Keyword(s):  
Grain Boundary ◽  
Solid Phase ◽  
Grain Boundary Wetting

Effect of Processing Temperature on Microstructure Development during ECAP of Al-Mg-Sc Alloy

2008 ◽  
Vol 584-586 ◽  
pp. 481-486 ◽  
Author(s):  
Oleg Sitdikov ◽  
Elena Avtokratova ◽  
Taku Sakai ◽  
Kaneaki Tsuzaki ◽  
Rustam Kaibyshev ◽  
...  
Keyword(s):  
Grain Boundary ◽  
Boundary Migration ◽  
Grain Structure ◽  
Coarse Grained ◽  
Microstructural Development ◽  
Al Alloy ◽  
Processing Temperature ◽  
Fine Grained ◽  
Grain Boundary Mobility ◽  
Angular Pressing

Microstructural evolution taking place during equal channel angular pressing (ECAP) was studied in a commercial coarse-grained Al-6%Mg-0.4%Mn-0.3%Sc alloy in a temperature interval 200- 450oC (~0.5-0.8 Tm). Samples were pressed using route A to a total strain of 12 and quenched in water after each ECAP pass. Uniform fine-grained microstructures with the average grain sizes of 0.7 and 2.5 0m, are almost fully evolved at high ECAP strains at 250oC and 450oC, respectively, while ECAP at 300oC (~0.6 Tm) leads to the formation of bimodal grain structure with fine grains of around 1 µm and relatively coarse grains of around 8 µm. The latter are developed due to the occurrence of static recrystallization during “keeping” time in the ECAP channel and/or reheating between ECAP passes. The microstructural development under warm-to-hot ECAP conditions is discussed in terms of the large potential for grain boundary migration resulted from an overlapping of accelerated grain boundary mobility at high pressing temperatures and enhanced driving force for recrystallization, which is caused by a strong inhibition of dynamic recovery in a heavily-alloyed Al alloy.

Contact angles by the solid-phase grain boundary wetting (coverage) in the Co–Cu system

2010 ◽  
Vol 45 (16) ◽  
pp. 4271-4275 ◽  
Author(s):  
B. B. Straumal ◽  
O. A. Kogtenkova ◽  
A. B. Straumal ◽  
Yu. O. Kuchyeyev ◽  
B. Baretzky
Keyword(s):  
Grain Boundary ◽  
Solid Phase ◽  
Contact Angles ◽  
Grain Boundary Wetting

Grain Boundary Wetting by a Second Solid Phase in Ti-Fe Alloys

2018 ◽  
Vol 27 (10) ◽  
pp. 4989-4992 ◽  
Author(s):  
A. S. Gornakova ◽  
B. B. Straumal ◽  
A. N. Nekrasov ◽  
A. Kilmametov ◽  
N. S. Afonikova
Keyword(s):  
Grain Boundary ◽  
Solid Phase ◽  
Grain Boundary Wetting ◽  
Fe Alloys

scholarly journals Grain Boundary Wetting by a Second Solid Phase in the High Entropy Alloys: A Review

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7506
Author(s):  
Boris B. Straumal ◽  
Anna Korneva ◽  
Gabriel A. Lopez ◽  
Alexei Kuzmin ◽  
Eugen Rabkin ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Grain Boundary ◽  
Solid Phase ◽  
High Entropy Alloys ◽  
Grain Boundary Engineering ◽  
Phase Form ◽  
High Entropy ◽  
The Matrix ◽  
Tie Lines ◽  
Grain Boundary Wetting

In this review, the phenomenon of grain boundary (GB) wetting by the second solid phase is analyzed for the high entropy alloys (HEAs). Similar to the GB wetting by the liquid phase, the GB wetting by the second solid phase can be incomplete (partial) or complete. In the former case, the second solid phase forms in the GB of a matrix, the chain of (usually lenticular) precipitates with a certain non-zero contact angle. In the latter case, it forms in the GB continuous layers between matrix grains which completely separate the matrix crystallites. The GB wetting by the second solid phase can be observed in HEAs produced by all solidification-based technologies. The particle chains or continuous layers of a second solid phase form in GBs also without the mediation of a liquid phase, for example by solid-phase sintering or coatings deposition. To describe the GB wetting by the second solid phase, the new GB tie-lines should be considered in the two- or multiphase areas in the multicomponent phase diagrams for HEAs. The GB wetting by the second solid phase can be used to improve the properties of HEAs by applying the so-called grain boundary engineering methods.

scholarly journals Grain Boundary Wetting Phenomena in High Entropy Alloys Containing Nitrides, Carbides, Borides, Silicides, and Hydrogen: A Review

Crystals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1540
Author(s):  
Boris Straumal ◽  
Eugen Rabkin ◽  
Gabriel A. Lopez ◽  
Anna Korneva ◽  
Alexei Kuzmin ◽  
...  
Keyword(s):  
Grain Boundary ◽  
Chemical Engineering ◽  
Solid Phase ◽  
Second Phase ◽  
High Entropy Alloys ◽  
High Entropy ◽  
The Matrix ◽  
Tie Lines ◽  
Grain Boundary Wetting ◽  
A Chain

In this review, we analyze the structure of multicomponent alloys without principal components (they are also called high entropy alloys—HEAs), containing not only metals but also hydrogen, nitrogen, carbon, boron, or silicon. In particular, we discuss the phenomenon of grain boundary (GB) wetting by the melt or solid phase. The GB wetting can be complete or incomplete (partial). In the former case, the grains of the matrix are completely separated by the continuous layer of the second phase (solid or liquid). In the latter case of partial GB wetting, the second solid phase forms, between the matrix grains, a chain of (usually lenticular) precipitates or droplets with a non-zero value of the contact angle. To deal with the morphology of GBs, the new GB tie-lines are used, which can be constructed in the two- or multiphase areas of the multidimensional HEAs phase diagrams. The GBs in HEAs in the case of complete or partial wetting can also contain hydrides, nitrides, carbides, borides, or silicides. Thus, GB wetting by the hydrides, nitrides, carbides, borides, or silicides can be used in the so-called grain boundary chemical engineering in order to improve the properties of respective HEAs.

scholarly journals Bulk and Surface Low Temperature Phase Transitions in the Mg-Alloy EZ33A

Metals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1127
Author(s):  
Alexander Straumal ◽  
Ivan Mazilkin ◽  
Kristina Tzoy ◽  
Boris Straumal ◽  
Krzysztof Bryła ◽  
...  
Keyword(s):  
Phase Transitions ◽  
Low Temperature ◽  
Grain Boundary ◽  
Solid Phase ◽  
Cast Alloy ◽  
Wetting Transition ◽  
Temperature Phase ◽  
Grain Boundary Wetting ◽  
Structure Assessment ◽  
Low Temperature Phase

Low-temperature phase transitions in the EZ33A Mg-cast alloy have been investigated. Based on the structure assessment of the alloy after annealing at 150 °C (1826 h) and at 200 °C (2371 h) a grain boundary wetting transition by a second solid phase was documented. Within a 50 °C temperature range, substantial differences in the α(Mg) grain boundary fraction wetted by the (Mg,Zn)12RE intermetallic were observed. In contrast to what was reported in the literature, two different types of precipitates were found within α(Mg) grains. With increasing annealing temperatures, both types of precipitates dissolved.

Solid-phase crystallization of ultra-thin amorphous Ge layers on insulators

2021 ◽  
Author(s):  
Ryo Oishi ◽  
Koji ASAKA ◽  
Bolotov Leonid ◽  
Noriyuki Uchida ◽  
Masashi Kurosawa ◽  
...  
Keyword(s):  
Grain Size ◽  
Grain Boundary ◽  
Barrier Height ◽  
Carrier Mobility ◽  
Solid Phase ◽  
Hole Mobility ◽  
Solid Phase Crystallization ◽  
Simple Method ◽  
20 Nm ◽  
Grain Boundary Barrier

Abstract A simple method to form ultra-thin (< 20 nm) semiconductor layers with a higher mobility on a 3D-structured insulating surface is required for next-generation nanoelectronics. We have investigated the solid-phase crystallization of amorphous Ge layers with thicknesses of 10−80 nm on insulators of SiO2 and Si3N4. We found that decreasing the Ge thickness reduces the grain size and increases the grain boundary barrier height, causing the carrier mobility degradation. We examined two methods, known effective to enhance the grain size in the thicker Ge (>100 nm). As a result, a relatively high Hall hole mobility (59 cm2/Vs) has been achieved with a 20-nm-thick polycrystalline Ge layer on Si3N4, which is the highest value among the previously reported works.

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