Unusual plastic deformation behavior of nanotwinned Cu/high entropy alloy FeCoCrNi nanolaminates

Nanoscale ◽  
2019 ◽  
Vol 11 (23) ◽  
pp. 11340-11350 ◽  
Author(s):  
Y. F. Zhao ◽  
J. Y. Zhang ◽  
Y. Q. Wang ◽  
K. Wu ◽  
G. Liu ◽  
...  

Contrary to the popular belief that the soft phase in bimetal multilayers plays the dominant role in plastic deformation, the hard FeCoCrNi high entropy alloys (HEA) phase makes more contribution to the deformation of Cu/HEA nanolaminates.

2018 ◽  
Vol 25 (2) ◽  
pp. 277-284 ◽  
Author(s):  
Min Ji Jang ◽  
Hyunjeong Kwak ◽  
Ye Won Lee ◽  
Youjin Jeong ◽  
Jahong Choi ◽  
...  

2022 ◽  
Vol 142 ◽  
pp. 107459
Author(s):  
Yuehuang Xie ◽  
Zhen Zhang ◽  
Yifei Luo ◽  
Jun Wang ◽  
Jiamiao Liang ◽  
...  

Entropy ◽  
2018 ◽  
Vol 20 (11) ◽  
pp. 889 ◽  
Author(s):  
Sanghita Mridha ◽  
Mageshwari Komarasamy ◽  
Sanjit Bhowmick ◽  
Rajiv Mishra ◽  
Sundeep Mukherjee

High entropy alloys (HEAs) have attracted widespread interest due to their unique properties at many different length-scales. Here, we report the fabrication of nanocrystalline (NC) Al0.1CoCrFeNi high entropy alloy and subsequent small-scale plastic deformation behavior via nano-pillar compression tests. Exceptional strength was realized for the NC HEA compared to pure Ni of similar grain sizes. Grain boundary mediated deformation mechanisms led to high strain rate sensitivity of flow stress in the nanocrystalline HEA.


2020 ◽  
Vol 143 (2) ◽  
Author(s):  
Prasanta K. Das ◽  
Vishal Kumar ◽  
Prasenjit Khanikar

Abstract High entropy alloys (HEAs) are primarily known for their high strength and high thermal stability. These alloys have recently been studied for high strain rate applications as well. HEAs have been observed to exhibit different properties when subjected to different strain rates. Very few published results on HEAs are available for high strain rate loading conditions. In addition, modeling and simulation work of microstructural details, such as grain boundary and precipitates of HEAs have not yet been investigated. However, at an atomistic length scale, molecular dynamics simulation works of HEAs have already been published. In this study, a detailed microstructural analysis of plastic deformation of the material under high strain rate loading has been performed using dislocation density based crystal plasticity finite element modeling. The primary objective is, therefore, to assess the strengthening effects due to precipitates on a particular high entropy alloy Al0.3CoCrFeNi with ultrafine grains having randomly distributed NiAl precipitates.


Entropy ◽  
2019 ◽  
Vol 21 (1) ◽  
pp. 54 ◽  
Author(s):  
Shunhua Chen ◽  
Jingyuan Wang ◽  
Lei Xia ◽  
Yucheng Wu

The plastic deformation of bulk metallic glasses (BMGs) depends significantly on applied stress states, and more importantly, in practical applications of BMGs as structural materials, they always deform under complex stress fields. The understanding of deformation behavior of BMGs under complex stress fields is important not only for uncovering the plastic deformation mechanisms of BMGs, but also for developing BMG components with excellent mechanical performance. In this article, we briefly summarize the recent research progress on the deformation behavior of BMGs under complex stress fields, including the formation and propagation of shear bands, tunable macroscopic plasticity, and serrated plastic flows. The effect of complex stress fields on the plastic deformation mechanisms of BMGs is discussed from simple stress gradient to tailored complex stress fields. The deformation behavior of high entropy alloys (HEAs) under complex stress states has also been discussed. Challenges, potential implications and some unresolved issues are proposed.


2020 ◽  
Vol 6 (37) ◽  
pp. eaaz4748 ◽  
Author(s):  
Chanho Lee ◽  
George Kim ◽  
Yi Chou ◽  
Brianna L. Musicó ◽  
Michael C. Gao ◽  
...  

Single-phase solid-solution refractory high-entropy alloys (HEAs) show remarkable mechanical properties, such as their high yield strength and substantial softening resistance at elevated temperatures. Hence, the in-depth study of the deformation behavior for body-centered cubic (BCC) refractory HEAs is a critical issue to explore the uncovered/unique deformation mechanisms. We have investigated the elastic and plastic deformation behaviors of a single BCC NbTaTiV refractory HEA at elevated temperatures using integrated experimental efforts and theoretical calculations. The in situ neutron diffraction results reveal a temperature-dependent elastic anisotropic deformation behavior. The single-crystal elastic moduli and macroscopic Young’s, shear, and bulk moduli were determined from the in situ neutron diffraction, showing great agreement with first-principles calculations, machine learning, and resonant ultrasound spectroscopy results. Furthermore, the edge dislocation–dominant plastic deformation behaviors, which are different from conventional BCC alloys, were quantitatively described by the Williamson-Hall plot profile modeling and high-angle annular dark-field scanning transmission electron microscopy.


2020 ◽  
Author(s):  
Congyan Zhang ◽  
Binbin Yue ◽  
Uttam Bhandari ◽  
Oleg Starovoytov ◽  
Yan Yang ◽  
...  

Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 540
Author(s):  
Mohamed Ali Hassan ◽  
Hossam M. Yehia ◽  
Ahmed S. A. Mohamed ◽  
Ahmed Essa El-Nikhaily ◽  
Omayma A. Elkady

To improve the AlCoCrFeNi high entropy alloys’ (HEAs’) toughness, it was coated with different amounts of Cu then fabricated by the powder metallurgy technique. Mechanical alloying of equiatomic AlCoCrFeNi HEAs for 25 h preceded the coating process. The established powder samples were sintered at different temperatures in a vacuum furnace. The HEAs samples sintered at 950˚C exhibit the highest relative density. The AlCoCrFeNi HEAs model sample was not successfully produced by the applied method due to the low melting point of aluminum. The Al element’s problem disappeared due to encapsulating it with a copper layer during the coating process. Because the atomic radius of the copper metal (0.1278 nm) is less than the atomic radius of the aluminum metal (0.1431 nm) and nearly equal to the rest of the other elements (Co, Cr, Fe, and Ni), the crystal size powder and fabricated samples decreased by increasing the content of the Cu wt%. On the other hand, the lattice strain increased. The microstructure revealed that the complete diffusion between the different elements to form high entropy alloy material was not achieved. A dramatic decrease in the produced samples’ hardness was observed where it decreased from 403 HV at 5 wt% Cu to 191 HV at 20 wt% Cu. On the contrary, the compressive strength increased from 400.034 MPa at 5 wt% Cu to 599.527 MPa at 15 wt% Cu with a 49.86% increment. This increment in the compressive strength may be due to precipitating the copper metal on the particles’ surface in the nano-size, reducing the dislocations’ motion, increasing the stiffness of produced materials. The formability and toughness of the fabricated materials improved by increasing the copper’s content. The thermal expansion has increased gradually by increasing the Cu wt%.


Sign in / Sign up

Export Citation Format

Share Document