Effect of Mo Addition on The Microstructure and Mechanical Properties of CoCuFeNi High Entropy Alloy

In order to reveal the effect of Mo addition on the microstructure and mechanical properties, (CoCuFeNi)100-xMox (x = 0, 10, 15, 19, and 25, x values in atomic ratio) high entropy alloys were prepared by vacuum arc-melting. The results showed that with Mo addition, the μ phase formed and serious separation occurred in the high entropy alloys. The content of μ phase increased with the increase in Mo content. The microstructure of the alloys changed from an initial single-phase face-center-cubic (FCC) solid solution structure (x = 0) to a hypoeutectic microstructure (x = 15), then to a full eutectic microstructure (x = 19), and finally to a hypereutectic microstructure (x = 25). Coherent interface between μ phase and FCC phase was observed. The (CoCuFeNi)81Mo19 alloy with fully eutectic microstructures exhibited the highest yield strength of 557 MPa and fracture strength of 767 MPa in tensile tests at room temperature. The fracture surface revealed that the formation of great amounts of the μ phase resulted in the loss of ductility of (CoCuFeNi)100-xMox alloys.

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Microstructure and Mechanical Properties of VTaTiMoAlx Refractory High Entropy Alloys

Materials Science Forum ◽

10.4028/www.scientific.net/msf.898.638 ◽

2017 ◽

Vol 898 ◽

pp. 638-642 ◽

Cited By ~ 7

Author(s):

Dong Xu Qiao ◽

Hui Jiang ◽

Xiao Xue Chang ◽

Yi Ping Lu ◽

Ting Ju Li

Keyword(s):

Mechanical Properties ◽

Vacuum Arc ◽

High Entropy Alloys ◽

X Ray Diffraction ◽

Dendrite Structure ◽

X Ray ◽

High Entropy ◽

Arc Melting ◽

Vacuum Arc Melting ◽

Microstructure And Mechanical Properties

A series of refractory high-entropy alloys VTaTiMoAlx with x=0,0.2,0.6,1.0 were designed and produced by vacuum arc melting. The effect of added Al elements on the microstructure and mechanical properties of refractory high-entropy alloys were investigated. The X-ray diffraction results showed that all the high-entropy alloys consist of simple BCC solid solution. SEM indicated that the microstructure of VTaTiMoAlx changes from equiaxial dendritic-like structure to typical dendrite structure with the addition of Al element. The composition of different regions in the alloys are obtained by energy dispersive spectroscopy and shows that Ta, Mo elements are enriched in the dendrite areas, and Al, Ti, V are enriched in inter-dendrite areas. The yield strength and compress strain reach maximum (σ0.2=1221MPa, ε=9.91%) at x=0, and decrease with the addition of Al element at room temperature. Vickers hardness of the alloys improves as the Al addition.

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Effects of Boron Content on microstructure and mechanical properties of AlFeCoNiBx High Entropy Alloy Prepared by vacuum arc melting

Vacuum ◽

10.1016/j.vacuum.2019.03.019 ◽

2019 ◽

Vol 164 ◽

pp. 212-218 ◽

Cited By ~ 10

Author(s):

Lili Hou ◽

Jiatao Hui ◽

Yuhong Yao ◽

Jian Chen ◽

Jiangnan Liu

Keyword(s):

Mechanical Properties ◽

Boron Content ◽

Vacuum Arc ◽

High Entropy Alloy ◽

High Entropy ◽

Arc Melting ◽

Vacuum Arc Melting ◽

Microstructure And Mechanical Properties

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Microstructure and Mechanical Properties of the W-Ni-Co System Refractory High-Entropy Alloys

Materials Science Forum ◽

10.4028/www.scientific.net/msf.816.324 ◽

2015 ◽

Vol 816 ◽

pp. 324-329 ◽

Cited By ~ 3

Author(s):

Hui Jiang ◽

Li Jiang ◽

Yi Ping Lu ◽

Tong Min Wang ◽

Zhi Qiang Cao ◽

...

Keyword(s):

Mechanical Properties ◽

Vacuum Arc ◽

High Entropy Alloys ◽

Face Centered Cubic ◽

High Entropy ◽

Melting Temperatures ◽

Arc Melting ◽

Microstructure And Mechanical Properties ◽

The Matrix ◽

Face Centered

The elements Mo, Cr and V were added to the W-Ni-Co system high entropy alloys, the effects of these added elements on microstructure and mechanical properties of these alloys were studied. The alloys were produced by vacuum arc melting. The compositions were W0.5Ni2Co2VMo0.5,W0.5Ni2Co2VCr0.5and W0.5Ni2Co2CrMo0.5(denoted as Alloy 1, Alloy 2 and Alloy 3) respectively. The theoretical melting temperatures were higher than 2000 K. X-ray diffraction, SEM and energy dispersive spectroscopy (EDS) results indicated that the matrix of the alloys is face-centered cubic (FCC) solid-solution, the alloys showed dendrite crystal structure. Ni, Co elements were enriched in the dendrite areas, the W, Mo were enriched in the inter-dendrite regions ,while V, Cr elements were uniform distribution. The Vickers hardness of these alloys was 376.1 HV, 255.88 HV and 306.8 HV, respectively. The yield strength values (σ0.2) of Alloy 1, Alloy 2 and Alloy 3 were approximately 1000MPa, 750MPa, 250MPa, respectively. The alloys show good compression plasticity deformation capacity at RT.

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Effect of Ta Addition on Structural Evolution and Mechanical Properties of the CoFeNi2W0.5 High Entropy Alloy

Materials Science Forum ◽

10.4028/www.scientific.net/msf.849.34 ◽

2016 ◽

Vol 849 ◽

pp. 34-39 ◽

Cited By ~ 3

Author(s):

Li Jiang ◽

Yong Dong ◽

Hui Jiang ◽

Yi Ping Lu ◽

Zhi Qiang Cao ◽

...

Keyword(s):

Mechanical Properties ◽

Vickers Hardness ◽

Solution Structure ◽

Structural Evolution ◽

Alloy System ◽

High Entropy Alloy ◽

Face Centered Cubic ◽

High Entropy ◽

Microstructure And Mechanical Properties ◽

Electron Microscopes

A series of CoFeNi2W0.5Tax (x = 0-0.6) high entropy alloys (HEAs) were synthesized by arc melting to investigate the alloying effect of Ta element on the microstructure and mechanical properties of the CoFeNi2W0.5 alloy system. Phase constitution, microstructure and mechanical properties of the alloys were analyzed by X-ray diffraction (XRD), scanning electron microscopes (SEM), Vickers hardness and compressive test. It was found that when x = 0, the alloy consists of a single-phase face-centered cubic (FCC) solid solution structure and exhibit excellent ductility, the compressive plastic elongation of which can reach 80% without fracture. While with increasing Ta content, the brittle Co2Ta-type Laves phase appears which leads to a decrease of the plastic strain and an increase of the yield strength, and the Vickers hardness shows an obvious increase from HV 179.5 to HV 753.2.

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Microstructure and Mechanical Properties of High-Entropy Alloys CoCrFeNiAl by Welding

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.936.1635 ◽

2014 ◽

Vol 936 ◽

pp. 1635-1640 ◽

Cited By ~ 4

Author(s):

Lang Cui ◽

Bing Ma ◽

Sheng Qiang Feng ◽

Xiu Ling Wang

Keyword(s):

Mechanical Properties ◽

Spot Welding ◽

Dendritic Morphology ◽

High Entropy Alloy ◽

High Entropy Alloys ◽

Common Elements ◽

High Entropy ◽

Grain Sizes ◽

Arc Melting ◽

Microstructure And Mechanical Properties

Five common elements Co, Cr, Fe, Ni and Al were selected, and CoCrFeNiAl was prepared by arc-melting. The microstructure and mechanical properties after spot welding were studied. The results show that the cast microstructure of high entropy alloy CoCrFeNiAl is relatively uniform with a dendritic morphology. The heat is inversely proportional with the alloy grain sizes. The greater the heat is, the smaller the grain size is, which leads to the higher hardness and more uniform tissue. But there is a critical value of the heat(Hcrit) in spot welding. When Hactu(actual heat) exceeds Hcrit, it will adversely affect the performance, resulting in crack, splash and other defects.

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