scholarly journals Effects of Mo, Nb, Ta, Ti, and Zr on Mechanical Properties of Equiatomic Hf-Mo-Nb-Ta-Ti-Zr Alloys

Entropy ◽  
2018 ◽  
Vol 21 (1) ◽  
pp. 15 ◽  
Author(s):  
Ko-Kai Tseng ◽  
Chien-Chang Juan ◽  
Shuen Tso ◽  
Hsuan-Chu Chen ◽  
Che-Wei Tsai ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Solid Solution Phase ◽  
Refractory Element ◽  
Strengthening Effect ◽  
Cast State ◽  
High Entropy ◽  
Pros And Cons ◽  
Solution Strengthening ◽  
Zr Alloys

Nowadays refractory high-entropy alloys (RHEAs) are regarded as great candidates for the replacement of superalloys at high temperature. To design a RHEA, one must understand the pros and cons of every refractory element. However, the elemental effect on mechanical properties remains unclear. In this study, the subtraction method was applied on equiatomic HfMoNbTaTiZr alloys to discover the role of each element, and, thus, HfMoNbTaTiZr, HfNbTaTiZr, HfMoTaTiZr, HfMoNbTiZr, HfMoNbTaZr, and HfMoNbTaTi were fabricated and analyzed. The microstructure and mechanical properties of each alloy at the as-cast state were examined. The solid solution phase formation rule and the solution strengthening effect are also discussed. Finally, the mechanism of how Mo, Nb, Ta, Ti, and Zr affect the HfMoNbTaTiZr alloys was established after comparing the properties of these alloys.

scholarly journals Microstructure and Mechanical Properties of TaNbVTiAlx Refractory High-Entropy Alloys

Entropy ◽  
2020 ◽  
Vol 22 (3) ◽  
pp. 282 ◽  
Author(s):  
Li Xiang ◽  
Wenmin Guo ◽  
Bin Liu ◽  
Ao Fu ◽  
Jianbo Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
High Entropy Alloys ◽  
Strengthening Effect ◽  
High Entropy ◽  
Solid Solution Strengthening ◽  
Specific Strength ◽  
Compression Properties ◽  
Uniform Microstructure ◽  
Solution Strengthening

A series of TaNbVTiAlx (x = 0, 0.2, 0.4, 0.6, 0.8, and 1.0) refractory high-entropy alloys (RHEAs) with high specific strength and reasonable plasticity were prepared using powder metallurgy (P/M) technology. This paper studied their microstructure and compression properties. The results show that all the TaNbVTiAlx RHEAs exhibited a single BCC solid solution microstructure with no elemental segregation. The P/M TaNbVTiAlx RHEAs showed excellent room-temperature specific strength (207.11 MPa*cm3/g) and high-temperature specific strength (88.37 MPa*cm3/g at 900 °C and 16.03 MPa*cm3/g at 1200 °C), with reasonable plasticity, suggesting that these RHEAs have potential to be applied at temperatures >1200 °C. The reasons for the excellent mechanical properties of P/M TaNbVTiAl0.2 RHEA were the uniform microstructure and solid solution strengthening effect.

Effect of Interstitial Elements on the Cryogenic Mechanical Behavior of FCC High Entropy Alloys

2021 ◽  
Vol 1016 ◽  
pp. 1386-1391
Author(s):  
Anastasia Semenyuk ◽  
Margarita Klimova ◽  
Sergey Zherebtsov ◽  
Nikita Stepanov
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Thermomechanical Processing ◽  
Induction Melting ◽  
High Entropy Alloys ◽  
Strengthening Effect ◽  
Face Centered Cubic ◽  
High Entropy ◽  
C And N ◽  
Interstitial Elements

High entropy alloys (HEAs) with face-centered cubic (fcc) structure, namely equiatomic CoCrFeMnNi alloy, have attracted considerable attention because of impressive cryogenic mechanical properties – strength, ductility, and fracture toughness. Further increase of the properties can be achieved, for example, by proper alloying. A particularly attractive option is the addition of interstitial elements like carbon or nitrogen. In present work, a series of CoCrFeMnNi-based alloys with different amounts of C and N (0-2 at.%) was prepared by induction melting. The alloys doped with C had lower Cr content to increase the solubility of carbon in the fcc solid solution. It was revealed that the solid solution strengthening effect of both C and N is significantly increased when the testing temperature decreases from 293K to 77K. The effect of thermomechanical processing on the structure and mechanical properties of the alloys is analyzed.

Role of second-phase particles in the microstructural evolution and mechanical properties of extruded Mg-Gd-Y-Ag-Zr alloys

2020 ◽  
Vol 24 ◽  
pp. 100956
Author(s):  
Fan Zhang ◽  
Yafei Wang ◽  
Yunbiao Duan ◽  
Kaijun Wang ◽  
Yutian Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Microstructural Evolution ◽  
Second Phase ◽  
Second Phase Particles ◽  
Zr Alloys

scholarly journals Effects of Silicon Content on the Microstructures and Mechanical Properties of (AlCrTiZrV)-Six-N High-Entropy Alloy Films

Entropy ◽  
2019 ◽  
Vol 21 (1) ◽  
pp. 75 ◽  
Author(s):  
Jingrui Niu ◽  
Wei Li ◽  
Ping Liu ◽  
Ke Zhang ◽  
Fengcang Ma ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Amorphous Phase ◽  
Silicon Content ◽  
High Entropy Alloy ◽  
Strengthening Effect ◽  
Nanocomposite Structure ◽  
High Entropy ◽  
Nanocrystalline Structures ◽  
Microstructures And Mechanical Properties

A series of (AlCrTiZrV)-Six-N films with different silicon contents were deposited on monocrystalline silicon substrates by direct-current (DC) magnetron sputtering. The films were characterized by the X-ray diffractometry (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), and nano-indentation techniques. The effects of the silicon content on the microstructures and mechanical properties of the films were investigated. The experimental results show that the (AlCrTiZrV)N films grow in columnar grains and present a (200) preferential growth orientation. The addition of the silicon element leads to the disappearance of the (200) peak, and the grain refinement of the (AlCrTiZrV)-Six-N films. Meanwhile, the reticular amorphous phase is formed, thus developing the nanocomposite structure with the nanocrystalline structures encapsulated by the amorphous phase. With the increase of the silicon content, the mechanical properties first increase and then decrease. The maximal hardness and modulus of the film reach 34.3 GPa and 301.5 GPa, respectively, with the silicon content (x) of 8% (volume percent). The strengthening effect of the (AlCrTiZrV)-Six-N film can be mainly attributed to the formation of the nanocomposite structure.

scholarly journals Additive Manufacturing of High-Entropy Alloys: A Review

Entropy ◽  
2018 ◽  
Vol 20 (12) ◽  
pp. 937 ◽  
Author(s):  
Shuying Chen ◽  
Yang Tong ◽  
Peter Liaw
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
High Efficiency ◽  
Mechanical Performance ◽  
Heating Temperature ◽  
Intermetallic Phase ◽  
Solid Solution Phase ◽  
High Entropy Alloys ◽  
Scanning Method ◽  
High Entropy

Owing to the reduced defects, low cost, and high efficiency, the additive manufacturing (AM) technique has attracted increasingly attention and has been applied in high-entropy alloys (HEAs) in recent years. It was found that AM-processed HEAs possess an optimized microstructure and improved mechanical properties. However, no report has been proposed to review the application of the AM method in preparing bulk HEAs. Hence, it is necessary to introduce AM-processed HEAs in terms of applications, microstructures, mechanical properties, and challenges to provide readers with fundamental understanding. Specifically, we reviewed (1) the application of AM methods in the fabrication of HEAs and (2) the post-heat treatment effect on the microstructural evolution and mechanical properties. Compared with the casting counterparts, AM-HEAs were found to have a superior yield strength and ductility as a consequence of the fine microstructure formed during the rapid solidification in the fabrication process. The post-treatment, such as high isostatic pressing (HIP), can further enhance their properties by removing the existing fabrication defects and residual stress in the AM-HEAs. Furthermore, the mechanical properties can be tuned by either reducing the pre-heating temperature to hinder the phase partitioning or modifying the composition of the HEA to stabilize the solid-solution phase or ductile intermetallic phase in AM materials. Moreover, the processing parameters, fabrication orientation, and scanning method can be optimized to further improve the mechanical performance of the as-built-HEAs.

Mechanical Properties and Marine Corrosion Resistance of P-Bearing ULCB Steels

2010 ◽  
Vol 654-656 ◽  
pp. 378-381 ◽  
Author(s):  
Wen Fang Cui ◽  
Chun Ming Liu ◽  
Si Xun Zhang
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Strengthening Effect ◽  
Marine Corrosion ◽  
Immersion Corrosion ◽  
P Content ◽  
Temperature Impact ◽  
Solution Strengthening ◽  
Low Temperature Impact Toughness ◽  
Inner Scale

The research aims to evaluate the microstructure, mechanical properties and marine corrosion resistance of P-bearing ULCB steels. P produced stronger solution strengthening effect, but had less effect on the low temperature impact toughness of ULCB steel. With increasing P content to 0.09(mass)%, the immersion corrosion rate of ULCB steel in 3.5% NaCl obviously decreased in comparison with those steels without or with lower P content. This is attributed to that the complex effect of Cu and P promoted the formation of dense amorphous oxyhydroxide in the inner scale, which inhibited further corrosion from NaCl solution. Mo in ULCB steel played an important role in avoiding pitting corrosion in Cl- environment.

Mechanical Properties of Ga1–xInxAs

1985 ◽  
Vol 53 ◽  
Author(s):  
S. Guruswamy ◽  
J.P. Hirth ◽  
K.T. Faber
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
High Temperature ◽  
Strengthening Effect ◽  
Plateau Stress ◽  
Solid Solution Strengthening ◽  
Stress Region ◽  
Solution Strengthening ◽  
Concentration Levels ◽  
Undoped Gaas

ABSTRACTSubstantial solid solution strengthening of GaAs by In acting as InAs4 units has recently been predicted. This strengthening could account for the reduction of dislocation density in GaAs single crystals grown from the melt. High temperature hardness measurements up to 700ºC have been carried out on (100) GaAs and Ga0.9975 In0.0025 As wafers. Results show a significant strengthening effect in In—doped GaAs even at concentration levels of about 0.2 wt%. A temperature independent flow stress region is observed for both these alloys. The In—doped GaAs shows ahigher plateau stress level compared to the undoped GaAs. The results are consistent with the solid solution strengthening model.

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