Strengthening Mechanisms in CoCrFeNiX0.4 (Al, Nb, Ta) High Entropy Alloys Fabricated by Powder Plasma Arc Additive Manufacturing

In high entropy alloys (HEAs), the addition of large-size atoms results in lattice distortion and further leads to solid solution strengthening or precipitation strengthening. However, the relationship between atomic radius, solid solution strengthening and precipitation strengthening has not been discerned yet. In this work, CoCrFeNiX0.4 (X = Al, Nb, Ta, with an equi-atomic radius) HEAs were prepared by powder plasma arc additive manufacturing (PPA-AM) and evaluated for their mechanical properties. Compression and nano-indentation hardness tests showed that the HEA with Ta showed the best properties. The influence of atomic radius and solid solubility on solid solution strengthening was investigated and the main strengthening mechanism that determines the mechanical properties of the developed HEAs was analyzed. The results showed that (i) the CoCrFeNiAl0.4 alloy did not show any solid solution strengthening effect and that a clear relation between solid solution strengthening and atomic size was not observed; (ii) in both CoCrFeNiTa0.4 and CoCrFeNiNb0.4 HEAs, precipitation strengthening and grain boundary strengthening effects are observed, wherein the difference in mechanical properties between both the alloys can be mainly attributed to the formation of fine eutectic structure in CoCrFeNiTa0.4; and (iii) from the microstructural analyses, it was identified that, in the CoCrFeNiTa0.4 HEA, the location containing a fine eutectic structure is accompanied by the formation of low-angle grain boundaries (LAGBs), which is also the region where deformed grains gather, giving rise to improved mechanical strengthening.

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(TiZrNbTa)-Mo high-entropy alloys: Dependence of microstructure and mechanical properties on Mo concentration and modeling of solid solution strengthening

Intermetallics ◽

10.1016/j.intermet.2018.01.017 ◽

2018 ◽

Vol 95 ◽

pp. 59-72 ◽

Cited By ~ 35

Author(s):

Shao-Ping Wang ◽

Jian Xu

Keyword(s):

Mechanical Properties ◽

Solid Solution ◽

High Entropy Alloys ◽

High Entropy ◽

Solid Solution Strengthening ◽

Microstructure And Mechanical Properties ◽

Solution Strengthening

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Microstructure and Mechanical Properties of TaNbVTiAlx Refractory High-Entropy Alloys

Entropy ◽

10.3390/e22030282 ◽

2020 ◽

Vol 22 (3) ◽

pp. 282 ◽

Cited By ~ 1

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.

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Lattice distortion as an estimator of solid solution strengthening in high-entropy alloys

Materials Characterization ◽

10.1016/j.matchar.2021.110877 ◽

2021 ◽

pp. 110877

Author(s):

Ankit Roy ◽

Praveen Sreeramagiri ◽

Tomas Babuska ◽

Brandon Krick ◽

Pratik K. Ray ◽

...

Keyword(s):

Solid Solution ◽

Lattice Distortion ◽

High Entropy Alloys ◽

High Entropy ◽

Solid Solution Strengthening ◽

Solution Strengthening

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Effect of Ti Element on Microstructure and Properties of Cu-Cr Alloy

Materials Science Forum ◽

10.4028/www.scientific.net/msf.817.307 ◽

2015 ◽

Vol 817 ◽

pp. 307-311 ◽

Cited By ~ 5

Author(s):

Peng Chao Zhang ◽

Jin Chuan Jie ◽

Yuan Gao ◽

Tong Min Wang ◽

Ting Ju Li

Keyword(s):

Mechanical Properties ◽

Solid Solution ◽

Spherical Shape ◽

Precipitation Strengthening ◽

Peak Hardness ◽

Ti Alloy ◽

Strengthening Mechanisms ◽

Vacuum Melting ◽

Solid Solution Strengthening ◽

Solution Strengthening

The Cu-Cr and Cu-Cr-Ti alloy plates were prepared by vacuum melting and plastic deformation. The effect of slight Ti element on microstructure and mechanical properties of Cu-Cr alloy was discussed. The result shows that Cr particles with spherical shape precipitated from Cu matrix after aging. Plenty Ti atoms dissolved in the vicinity of Cr particles and there were still parts of solid solution Ti atoms in other regions. Improvements in peak hardness and softening resistance were achieved with the addition of Ti element in Cu-Cr alloy. The addition of 0.1 wt.% Ti element makes Cu-Cr alloy possess tensile strength of 565 MPa and hardness of 185.9 HV after aging at 450 °C for 120 min, which can be attributed to multiple strengthening mechanisms, i.e. work hardening, solid solution strengthening and precipitation strengthening.

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