scholarly journals The effect of cooling rate on structure and mechanical properties of Co-Cr-Cu-Fe-Ni-Sn high entropy alloys

2021 ◽  
Vol 29 (1) ◽  
pp. 85-90
Author(s):  
O. I. Kushnerov ◽  
V. F. Bashev

The paper examines the structure and mechanical properties of multicomponent high-entropy CoCrCuFeNiSnx alloys in as-cast and splat-quenched states. The compositions of investigated alloys is analyzed by using the criteria for predicting the phase composition of high-entropy alloys available in the literature, based both on calculations of the entropy and enthalpy of mixing and on an estimate of the difference between the atomic radii of the component. The alloy films is fabricated by the known technique of splat-quenching. A cooling rate estimated by a film thickness is ~ 106 K/s. The simultaneous formation of two solid solutions (FCC + ordered BCC) has been established in the alloy structure. An increase in the concentration of Sn favors the formation of the ordered (В2 type) solid solution in the structure of the alloys. High values of the microhardness and dislocation density have been obtained in the splat-quenched samples. It is also shown that an increase in the Sn content positively affects the microhardness.


2018 ◽  
Vol 26 (1) ◽  
pp. 39-44
Author(s):  
O. I. Kushnerov ◽  
V. F. Bashev

The paper explores the structure and magnetic properties of multicomponent high-entropy Al-Cu-Fe-Ni-Si alloys in as-cast and splat-quenched state. This alloy system is characterized by the absence of expensive components, such as Co, V, Mo, Cr, usually used for the production of high-entropy alloys while its characteristics are not inferior to those of more expensive alloys. Components of the studied high-entropy alloys were selected taking into account both criteria for designing and estimating their phase composition, which are available in the literature and based on the calculations of the entropy and enthalpy of mixing, and the difference between atomic radii of components as well. The alloy films were fabricated by a known technique of splat-quenching. A cooling rate estimated by film thickness was ~ 106 K/s. Experimental results reveal that the studied alloys except the Al0.5CuFeNi one are multiphase, with the structure consisting of disordered BCC and FCC solid solutions. The Al0.5CuFeNi alloy has only FCC phase. The leading role in determining the type of solid solution formed in the studied high-entropy films obviously plays an element with the highest melting point. All of the investigated multicomponent films are soft magnetic materials as indicated by low values of coercivity, while most of the as-cast alloys are hard-magnetic.



2017 ◽  
Vol 132 ◽  
pp. 392-399 ◽  
Author(s):  
Yukun Lv ◽  
Ruyi Hu ◽  
Zhihao Yao ◽  
Jian Chen ◽  
Dapeng Xu ◽  
...  


Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 833
Author(s):  
Zhenhua Wang ◽  
Dongming Jin ◽  
Jincan Han ◽  
Qing Wang ◽  
Zhongwei Zhang ◽  
...  

In this work, the microstructural evolution and mechanical properties of new body-centered cubic (BCC)-based Al-Ti-Zr-Nb-Ta-Mo-V refractory high-entropy alloys (RHEAs) with coherent B2 precipitation are investigated. These designed alloy ingots were solid-solutionized at 1573 K for 2 h and then aged at 873 K for 24 h, in which each treatment was followed by water quenching. It was found that there exists phase separation of BCC matrix, Ti/Zr-rich BCC1 and Nb/Ta-rich BCC2 in these alloys. Moreover, ultra-fine spherical B2 nanoparticles with a size of 3~5 nm were dispersed in BCC2 matrix. These B2 nanoparticles could be coarsened up to 25~50 nm after aging and the particle morphology also changes to a cuboidal shape due to a moderate lattice misfit (ε = 0.7~2.0%). Also, Zr5Al3 phase could coexist with the B2 phase, where the difference between them is that the Ti element is enriched in B2 phase, rather than in Zr5Al3. Among them, the solutionized Al2Ti5Zr4Nb2.5Ta2.5 RHEAs exhibit good compressive mechanical property with a high yield strength of 1240 MPa and a large plasticity, which is mainly attributed to the coherent precipitation in the BCC matrix.



2017 ◽  
Vol 694 ◽  
pp. 61-67 ◽  
Author(s):  
Lili Ma ◽  
Cheng Li ◽  
Yiling Jiang ◽  
Jinlian Zhou ◽  
Lu Wang ◽  
...  


2020 ◽  
Vol 2020 (4) ◽  
pp. 16-22
Author(s):  
A.I. Ustinov ◽  
◽  
V.S. Skorodzievskii ◽  
S.A. Demchenkov ◽  
S.S. Polishchuk ◽  
...  


2021 ◽  
Vol 282 ◽  
pp. 128736 ◽  
Author(s):  
Qingkai Shen ◽  
Xiangdong Kong ◽  
Xizhang Chen ◽  
Xukai Yao ◽  
Vladislav B. Deev ◽  
...  


Author(s):  
Agnivesh Kumar Sinha ◽  
Vinay Kumar Soni ◽  
Rituraj Chandrakar ◽  
Anil Kumar


2021 ◽  
Vol 865 ◽  
pp. 158592
Author(s):  
Qing Liu ◽  
Guofeng Wang ◽  
Xiaochong Sui ◽  
Ye Xu ◽  
Yongkang Liu ◽  
...  


2021 ◽  
Vol 11 (6) ◽  
pp. 2832
Author(s):  
Haibo Liu ◽  
Cunlin Xin ◽  
Lei Liu ◽  
Chunqiang Zhuang

The structural stability of high-entropy alloys (HEAs) is closely related to their mechanical properties. The precise control of the component content is a key step toward understanding their structural stability and further determining their mechanical properties. In this study, first-principle calculations were performed to investigate the effects of different contents of each component on the structural stability and mechanical properties of Co-Cr-Fe-Ni HEAs based on the supercell model. Co-Cr-Fe-Ni HEAs were constructed based on a single face-centered cubic (FCC) solid solution. Elemental components have a clear effect on their structure and performance; the Cr and Fe elements have an obvious effect on the structural stability and equilibrium lattice constant, respectively. The Ni elements have an obvious effect on stiffness. The Pugh ratios indicate that Cr and Ni addition may increase ductility, whereas Co and Fe addition may decrease it. With increasing Co and Fe contents or decreasing Cr and Ni contents, the structural stability and stiffness of Co-Cr-Fe-Ni HEAs are improved. The structural stability and mechanical properties may be related to the strength of the metallic bonding and covalent bonding inside Co-Cr-Fe-Ni HEAs, which, in turn, is determined by the change in element content. Our results provide the underlying insights needed to guide the optimization of Co-Cr-Fe-Ni HEAs with excellent mechanical properties.



Sign in / Sign up

Export Citation Format

Share Document