Solid State Amorphization and Alloy Parameters for High Entropy Alloys

2021 ◽  
Vol 1016 ◽  
pp. 990-996
Author(s):  
Takeshi Nagase
Keyword(s):  
Solid Solution ◽  
Solid State ◽  
Intermetallic Compounds ◽  
Electron Irradiation ◽  
Fast Electron ◽  
High Entropy Alloy ◽  
Solid Solution Formation ◽  
High Entropy ◽  
Solution Formation ◽  
State Amorphization

Fast electron irradiation can induce the solid-state amorphization (SSA) of many intermetallic compounds. The occurrence of SSA stimulated by fast electron irradiation was found in the Al0.5TiZrPdCuNi high-entropy alloy (HEA). The relationship between the occurrence of SSA in intermetallic compounds under fast electron irradiation and the empirical alloy parameters for predicting the solid-solution-formation tendency in HEAs was discussed. The occurrence of SSA in intermetallic compounds was hardly predicted, only by the alloy parameters of δ or ΔHmix, which have been widely used for predicting solid-solution formation in HEAs. All intermetallic compounds with ΔHmix ≤ -35 kJ/mol and those with δ ≥ 12.5 exhibit the occurrence of SSA. This implies that the intermetallic compounds with a largely negative ΔHmix value and a largely positive δ parameter are favorable for the occurrence of SSA.

Solid-state amorphization in a Ti2Pd intermetallic compound under fast-electron irradiation

2013 ◽  
Vol 581 ◽  
pp. 324-329 ◽  
Author(s):  
Satoshi Anada ◽  
Takeshi Nagase ◽  
Hidehiro Yasuda ◽  
Hirotaro Mori
Keyword(s):  
Solid State ◽  
Intermetallic Compound ◽  
Electron Irradiation ◽  
Fast Electron ◽  
State Amorphization

scholarly journals Microstructure and Shear Strength of Brazing High Entropy TiZrHfNbMo Alloy and Si3N4 Ceramics Joints

Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 472
Author(s):  
Xiaohong Wang ◽  
Duo Dong ◽  
Xiaohong Yang ◽  
Peng Huang ◽  
Kangqiao Shi ◽  
...  
Keyword(s):  
Solid Solution ◽  
Shear Strength ◽  
Intermetallic Compounds ◽  
Reaction Layer ◽  
Interfacial Microstructure ◽  
High Entropy Alloy ◽  
Si3n4 Ceramic ◽  
High Entropy ◽  
Brazed Joints ◽  
Brazed Joint

The effects of different brazing processes on the interfacial microstructure and shear strength of TiZrHfNbMo high-entropy alloy (HEAS) and Si3N4 ceramic brazed joints were studied. There is no obvious defect in a brazed TiZrHfNbMo HEAS/AgCuTi/Si3N4 ceramic joint, and the two materials have good metallurgical bonding. The typical interface microstructure is Si3N4/Ti5Si3/Ag solid solution +Cu (s,s)+ CuTi/Cu2Ti/Cu4Ti + TiCu(Hf,Zr)NbMo/TiZrHfNbMo HEAs. With the increase of brazing temperature, the dispersed CuTi phase agglomerates in the brazed joint, and acts as the nucleate of the Cu-based solid solution. The thickness of the reaction layer increases with the increase of phases in the reaction layer on both sides of the joint. When the brazing temperature is 800 °C, 820 °C, 840 °C and 860 °C, the shear strength of the brazed joint is 30 MPa, 72 MPa, 86 MPa and 21 MPa, respectively. The formation of CuTi and Ti5Si3 intermetallic compounds increases the thickness of the reaction layer, and improves the strength of the joint. However, excessive CuTi and Ti5Si3 intermetallic compounds lead to a significant decrease in joint strength. The grain coarsening of the joint can also affect the strength of the joint.

Solid-state amorphization by electron irradiation

1988 ◽  
Vol 46 ◽  
pp. 462-463
Author(s):  
D.E. Luzzi
Keyword(s):  
Solid State ◽  
Intermetallic Compounds ◽  
Electron Irradiation ◽  
Low Temperatures ◽  
Image Sequence ◽  
Bright Field Image ◽  
Fixed Position ◽  
Bright Field ◽  
State 1 ◽  
State Amorphization

When certain intermetallic compounds are irradiated with ballistic electrons at low temperatures, the crystal becomes unstable and transforms into an amorphous phase. This electron irradiation induced crystalline to amorphous (C-A) transition is one of a recently discovered class of amorphization processes which occur in the solid state [1]. The relative simplicity of electron-matter interactions, and the ability to follow the transition inside the microscope, make the electron induced C-A transition ideal for the study of these amorphization processes.A bright field image sequence which depicts several features of the C-A transition is shown in the figure. In this example, CuTim was irradiated with 2 MeV electrons at 191 K (9.2 x 1023 e/m2-s; 5.5 x 10-3 dpa/s). The arrows mark a fixed position. In the images, taken after different irradiation times (a:30s, b:60s c:300s), the transition is evident from the distortion of the bend contour around the irradiated area.

scholarly journals Single crystal to single crystal [2+2] photoreactions in chloride and sulphate salts of 4-amino-cinnamic acid via solid-solution formation: a structural and kinetic study

2016 ◽  
Vol 52 (9) ◽  
pp. 1899-1902 ◽  
Author(s):  
Simone d'Agostino ◽  
Floriana Spinelli ◽  
Elisa Boanini ◽  
Dario Braga ◽  
Fabrizia Grepioni
Keyword(s):  
Solid Solution ◽  
Solid State ◽  
Single Crystal ◽  
Kinetic Study ◽  
Cinnamic Acid ◽  
State Solution ◽  
Solid Solution Formation ◽  
Solution Formation ◽  
Sulfate Salts ◽  
Sulphate Salts

SCSC [2+2] photodimerizationviathe formation of solid state solution is achieved in chloride and sulfate salts of 4-amino-cinnamic acid, and structural and kinetic analyses have been performed.

Solid Solution Formation Criteria for High Entropy Alloys

2007 ◽  
Vol 561-565 ◽  
pp. 1337-1339 ◽  
Author(s):  
Yong Zhang ◽  
Yun Jun Zhou
Keyword(s):  
Solid Solution ◽  
Enthalpy Of Mixing ◽  
Atomic Ratio ◽  
Size Difference ◽  
Atomic Size ◽  
Solid Solution Formation ◽  
Absolute Value ◽  
High Entropy ◽  
Solution Formation ◽  
Atomic Size Difference

The solid solution formation criteria for the equi-atomic ratio alloys were discussed. It is found that higher entropy of mixing (Smix>1.61R), less atomic size difference (δ<4.6), and near zero of the absolute value of the enthalpy of mixing (-2.685δ-2.54<Hmix <-1.28δ+5.44 KJ/mol) facilitate the formation of solid solution for the multi-principle components equi-atomic alloys.

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