Amorphization, mechano-crystallization, and crystallization kinetics of mechanically alloyed AlFeCuZnTi high-entropy alloys

2021 ◽  
pp. 131098
Author(s):  
Sara Daryoush ◽  
Hamed Mirzadeh ◽  
Abolghasem Ataie
Keyword(s):  
Crystallization Kinetics ◽  
High Entropy Alloys ◽  
Mechanically Alloyed ◽  
High Entropy ◽  
Kinetics Of

scholarly journals The Effect of Al on the Formation of a CrTaO4 Layer in Refractory High Entropy Alloys Ta-Mo-Cr-Ti-xAl

2021 ◽  
Author(s):  
S. Schellert ◽  
B. Gorr ◽  
H.- J. Christ ◽  
C. Pritzel ◽  
S. Laube ◽  
...  
Keyword(s):  
Mass Gain ◽  
Positive Influence ◽  
High Entropy Alloys ◽  
Oxide Scales ◽  
Temperature Oxidation ◽  
Internal Corrosion ◽  
High Entropy ◽  
Continuous Mass ◽  
Oxide Substrate ◽  
Kinetics Of

AbstractIn this study, the effect of Al on the high temperature oxidation of Al-containing refractory high entropy alloys (RHEAs) Ta-Mo-Cr-Ti-xAl (x = 5; 10; 15; 20 at%) was examined. Oxidation experiments were performed in air for 24 h at 1200 °C. The oxidation kinetics of the alloy with 5 at% Al is notably affected by the formation of gaseous MoO3 and CrO3, while continuous mass gain was detected for alloys with the higher Al concentrations. The alloys with 15 and 20 at% Al form relatively thin oxide scales and a zone of internal corrosion due to the formation of dense CrTaO4 scales at the interface oxide/substrate. The alloys with 5 and 10 at% Al exhibit, on the contrary, thick and porous oxide scales because of fast growing Ta2O5. The positive influence of Al on the formation of Cr2O3 followed by the growth of CrTaO4 to yield a compact scale is explained by getter and nucleation effects.

scholarly journals Thermodynamics and Kinetics of High-Entropy Alloys

2021 ◽  
Author(s):  
Michael C. Gao ◽  
Raymundo Arróyave ◽  
John E. Morral ◽  
Ursula R. Kattner
Keyword(s):  
High Entropy Alloys ◽  
High Entropy ◽  
Thermodynamics And Kinetics ◽  
Kinetics Of

Phase formation in mechanically alloyed AlxCoCrCuFeNi (x = 0.45, 1, 2.5, 5 mol) high entropy alloys

2013 ◽  
Vol 32 ◽  
pp. 119-126 ◽  
Author(s):  
R. Sriharitha ◽  
B.S. Murty ◽  
Ravi S. Kottada
Keyword(s):  
Phase Formation ◽  
High Entropy Alloys ◽  
Mechanically Alloyed ◽  
High Entropy

scholarly journals Kinetic ways of tailoring phases in high entropy alloys

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Feng He ◽  
Zhijun Wang ◽  
Yiyan Li ◽  
Qingfeng Wu ◽  
Junjie Li ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Equilibrium Phase ◽  
High Entropy Alloys ◽  
Kinetic Effect ◽  
Phase Selection ◽  
High Entropy ◽  
Comprehensive Performance ◽  
Sluggish Diffusion ◽  
Kinetics Of ◽  
Theoretical Analyses

Abstract The comprehensive performance of high entropy alloys (HEAs) depends on the phase selection significantly. However, up to now, investigations of the phase selection in HEAs mainly focused on the thermodynamic equilibrium phase, while kinetic ways of tailoring the phases in HEAs are seldom considered. In HEAs, the kinetics of sluggish diffusion and the numerous possible phases make the kinetics of phase transformation more complex and intriguing. Here, the kinetic effect in CoCrFeNiTi0.4 HEAs was investigated to reveal the possibility of controlling phase selection via kinetic ways for HEAs. The σ, γ′ and R phases in the CoCrFeNiTi0.4 HEA can be controlled under different cooling rate both in solidification and solid transformation. The theoretical analyses revealed the kinetic effect on phase selection. The method proposed here, tailoring the phases with different kinetic ways, could be used to prepare promising HEAs with very rich composition design.

scholarly journals Tungsten Matrix Composite Reinforced with CoCrFeMnNi High-Entropy Alloy: Impact of Processing Routes on Microstructure and Mechanical Properties

Metals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 992 ◽  
Author(s):  
P. V. Satyanarayana ◽  
R. Sokkalingam ◽  
P. K. Jena ◽  
K. Sivaprasad ◽  
K. G. Prashanth
Keyword(s):  
Heating Rate ◽  
Microwave Sintering ◽  
Oxide Phase ◽  
High Entropy Alloy ◽  
High Entropy Alloys ◽  
Mechanically Alloyed ◽  
High Entropy ◽  
Plasma Sintering ◽  
Conventional Sintering ◽  
Spark Plasma

Tungsten heavy alloy composite was developed by using novel CoCrFeMnNi high-entropy alloy as the binder/reinforcement phase. Elemental tungsten (W) powder and mechanically alloyed CoCrFeMnNi high-entropy alloy were mixed gently in high energy ball mill and consolidated using different sintering process with varying heating rate (in trend of conventional sintering < microwave sintering < spark plasma sintering). Mechanically alloyed CoCrFeMnNi high-entropy alloy have shown a predominant face-centered cubic (fcc) phase with minor Cr-rich σ-phase. Consolidated tungsten heavy high-entropy alloys (WHHEA) composites reveal the presence of Cr–Mn-rich oxide phase in addition to W-grains and high-entropy alloys (HEA) phase. An increase in heating rate restricts the tungsten grain growth with reduces the volume fraction of the Cr–Mn-rich phase. Finally, spark plasma sintering with a higher heating rate and shorter sintering time has revealed higher compressive strength (~2041 MPa) than the other two competitors (microwave sintering: ~1962 MPa and conventional sintering: ~1758 MPa), which may be attributed to finer W-grains and reduced fraction of Cr–Mn rich oxide phase.

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