scholarly journals Effects of Nitrogen Content on the Structure and Mechanical Properties of (Al0.5CrFeNiTi0.25)Nx High-Entropy Films by Reactive Sputtering

Entropy ◽  
2018 ◽  
Vol 20 (9) ◽  
pp. 624 ◽  
Author(s):  
Yong Zhang ◽  
Xue-Hui Yan ◽  
Wei-Bing Liao ◽  
Kun Zhao
Keyword(s):  
Solid Solution ◽  
Nitrogen Content ◽  
Alloy System ◽  
Size Difference ◽  
Face Centered Cubic ◽  
High Entropy ◽  
Atomic Size Difference ◽  
Bcc Structure ◽  
Face Centered ◽  
Bcc Phase

In this study, (Al0.5CrFeNiTi0.25)Nx high-entropy films are prepared by a reactive direct current (DC) magnetron sputtering at different N2 flow rates on silicon wafers. It is found that the structure of (Al0.5CrFeNiTi0.25)Nx high-entropy films is amorphous, with x = 0. It transforms from amorphous to a face-centered-cubic (FCC) structure with the increase of nitrogen content, while the bulk Al0.5CrFeNiTi0.25 counterpart prepared by casting features a body-centered-cubic (BCC) phase structure. The phase formation can be explained by the atomic size difference (δ). Lacking nitrogen, δ is approximately 6.4% for the five metal elements, which is relatively large and might form a BCC or ordered-BCC structure, while the metallic elements in this alloy system all have a trend to form nitrides like TiN, CrN, AlN, and FeN. Therefore, nitride components are becoming very similar in size and structure and solve each other easily, thus, an FCC (Al-Cr-Fe-Ni-Ti)N solid solution forms. The calculated value of δ is approximately 23% for this multicomponent nitride solid solution. The (Al0.5CrFeNiTi0.25)Nx films achieve a pronounced hardness and a Young’s modulus of 21.45 GPa and 253.8 GPa, respectively, which is obviously much higher than that of the as-cast Al0.5CrFeNiTi0.25 bulk alloys.

scholarly journals Magnetic Properties and Microstructure of FeCoNi(CuAl)0.8Snx (0 ≤ x ≤ 0.10) High-Entropy Alloys

Entropy ◽  
2018 ◽  
Vol 20 (11) ◽  
pp. 872 ◽  
Author(s):  
Zhong Li ◽  
Chenxu Wang ◽  
Linye Yu ◽  
Yong Gu ◽  
Minxiang Pan ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
High Entropy Alloys ◽  
Face Centered Cubic ◽  
High Tc ◽  
Soft Magnets ◽  
High Entropy ◽  
Face Centered ◽  
Fcc Phase ◽  
Bcc Phase ◽  
Curie Temperatures

The present work exhibits the effects of Sn addition on the magnetic properties and microstructure of FeCoNi(CuAl)0.8Snx (0 ≤ x ≤ 0.10) high-entropy alloys (HEAs). The results show all the samples consist of a mixed structure of face-centered-cubic (FCC) phase and body-centered-cubic (BCC) phase. The addition of Sn promotes the formation of BCC phase, and it also affects the shape of Cu-rich nano-precipitates in BCC matrix. It also shows that the Curie temperatures (Tc) of the FCC phase and the saturation magnetization (Ms) of the FeCoNi(CuAl)0.8Snx (0 ≤ x ≤ 0.10) HEAs increase greatly while the remanence (Br) decreases after the addition of Sn into FeCoNi(CuAl)0.8 HEA. The thermomagnetic curves indicate that the phases of the FeCoNi(CuAl)0.8Snx (0 ≤ x ≤ 0.10) HEAs will transform from FCC with low Tc to BCC phase with high Tc at temperature of 600–700 K. This work provides a new idea for FeCoNi(CuAl)0.8Snx (0 ≤ x ≤ 0.10) HEAs for their potential application as soft magnets to be used at high temperatures.

Selection of High Entropy Alloy for Solid Solution Using Multi-Criteria Decision Making Tool

2019 ◽  
Vol 969 ◽  
pp. 466-471
Author(s):  
Vinay Kumar Soni ◽  
Shubhashis Sanyal ◽  
Sudip Kumar Sinha
Keyword(s):  
Solid Solution ◽  
Vital Role ◽  
Size Difference ◽  
High Entropy Alloy ◽  
High Entropy Alloys ◽  
High Entropy ◽  
Atomic Size Difference ◽  
Topological Parameter ◽  
Topsis Technique ◽  
Selection Of

High entropy alloys (HEA’s) have found a very special place in aerospace industries due to their property of forming solid solution. In past literatures on high entropy alloys, it is established that parameters like atomic size difference (), topological parameter (Ω) and electro-negativity difference (∆) plays a vital role in deciding whether solid solution will be formed or not. Therefore, the present study deals with the selection of optimal high entropy composition based on the three parameters δ, Ω and with the help of TOPSIS (Technique for Order of Preference by Similarity to Ideal Solution). Ranking is done for 38 HEA different compositions such that the first rank represents the HEA which is most likely to form solid solution. The study reveals that TOPSIS method can be successfully implemented to predict the formation of solid solution in HEA’s.

Microstructure and Tensile Properties of Al0.5CoCrCuFeNi High-Entropy Alloy

2013 ◽  
Vol 456 ◽  
pp. 494-497 ◽  
Author(s):  
Hong Fei Sheng ◽  
Liang Ming Peng
Keyword(s):  
Solid Solution ◽  
Tensile Strength ◽  
Tensile Stress ◽  
Grain Boundaries ◽  
Cast Alloy ◽  
Ultimate Tensile Stress ◽  
High Entropy Alloy ◽  
Face Centered Cubic ◽  
High Entropy ◽  
Face Centered

The Al0.5CoCrFeCuNi alloy with equiaxed structure was prepared. The as-cast alloy consists of face-centered cubic (FCC) solid-solution with equiaxed matrix and network grain boundaries. Annealing/quenching treatment at 600°C promotes the formations of new BCC structured phase and Cu-rich nanoprecipitations dispersed in grain boundaries, which are beneficial for enhancement in Vickers Hardness and tensile strength. The ultimate tensile stress up to 1002 MPa was achieved after the alloy was annealed following quenching treatment.

Solid Solution Formation Criteria for High Entropy Alloys

2007 ◽  
Vol 561-565 ◽  
pp. 1337-1339 ◽  
Author(s):  
Yong Zhang ◽  
Yun Jun Zhou
Keyword(s):  
Solid Solution ◽  
Enthalpy Of Mixing ◽  
Atomic Ratio ◽  
Size Difference ◽  
Atomic Size ◽  
Solid Solution Formation ◽  
Absolute Value ◽  
High Entropy ◽  
Solution Formation ◽  
Atomic Size Difference

The solid solution formation criteria for the equi-atomic ratio alloys were discussed. It is found that higher entropy of mixing (Smix>1.61R), less atomic size difference (δ<4.6), and near zero of the absolute value of the enthalpy of mixing (-2.685δ-2.54<Hmix <-1.28δ+5.44 KJ/mol) facilitate the formation of solid solution for the multi-principle components equi-atomic alloys.

TENSILE AND COMPRESSIVE MECHANICAL BEHAVIOR OF A CoCrCuFeNiAl0.5 HIGH ENTROPY ALLOY

2009 ◽  
Vol 23 (06n07) ◽  
pp. 1254-1259 ◽  
Author(s):  
FANGJUN WANG ◽  
YONG ZHANG ◽  
GUOLIANG CHEN ◽  
HYWEL A. DAVIES
Keyword(s):  
Solid Solution ◽  
Solution Phase ◽  
High Entropy Alloy ◽  
Solid Solution Phase ◽  
Face Centered Cubic ◽  
Compressive Properties ◽  
Large Plastic Strain ◽  
High Entropy ◽  
Strain Limit ◽  
Face Centered

A high entropy alloy of composition CoCrCuFeNiAl 0.5 is mainly composed of a face centered cubic (FCC) solid solution phase. The tensile and compressive properties of the alloy were investigated; the alloy exhibited a tensile strength of 707 MPa, together with a large plastic strain limit of 19%.

scholarly journals Nanoporous Quasi-High-Entropy Alloy Microspheres

Metals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 345 ◽  
Author(s):  
Lianzan Yang ◽  
Yongyan Li ◽  
Zhifeng Wang ◽  
Weimin Zhao ◽  
Chunling Qin
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
High Specific Surface Area ◽  
High Entropy Alloy ◽  
Face Centered Cubic ◽  
High Entropy ◽  
Hierarchical Porous

High-entropy alloys (HEAs) present excellent mechanical properties. However, the exploitation of chemical properties of HEAs is far less than that of mechanical properties, which is mainly limited by the low specific surface area of HEAs synthesized by traditional methods. Thus, it is vital to develop new routes to fabricate HEAs with novel three-dimensional structures and a high specific surface area. Herein, we develop a facile approach to fabricate nanoporous noble metal quasi-HEA microspheres by melt-spinning and dealloying. The as-obtained nanoporous Cu30Au23Pt22Pd25 quasi-HEA microspheres present a hierarchical porous structure with a high specific surface area of 69.5 m2/g and a multiphase approximatively componential solid solution characteristic with a broad single-group face-centered cubic XRD pattern, which is different from the traditional single-phase or two-phase solid solution HEAs. To differentiate, these are named quasi-HEAs. The synthetic strategy proposed in this paper opens the door for the synthesis of porous quasi-HEAs related materials, and is expected to promote further applications of quasi-HEAs in various chemical fields.

scholarly journals Development of Novel Lightweight Al-Rich Quinary Medium-Entropy Alloys with High Strength and Ductility

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4223
Author(s):  
Po-Sung Chen ◽  
Yu-Chin Liao ◽  
Yen-Ting Lin ◽  
Pei-Hua Tsai ◽  
Jason S. C. Jang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Compressive Strain ◽  
High Strength ◽  
Fine Tuning ◽  
Face Centered Cubic ◽  
Transportation Industry ◽  
High Entropy ◽  
Good Potential ◽  
Face Centered

Most high-entropy alloys and medium-entropy alloys (MEAs) possess outstanding mechanical properties. In this study, a series of lightweight nonequiatomic Al50–Ti–Cr–Mn–V MEAs with a dual phase were produced through arc melting and drop casting. These cast alloys were composed of body-centered cubic and face-centered cubic phases. The density of all investigated MEAs was less than 5 g/cm3 in order to meet energy and transportation industry requirements. The effect of each element on the microstructure evolution and mechanical properties of these MEAs was investigated. All the MEAs demonstrated outstanding compressive strength, with no fractures observed after a compressive strain of 20%. Following the fine-tuning of the alloy composition, the Al50Ti20Cr10Mn15V5 MEA exhibited the most compressive strength (~1800 MPa) and ductility (~34%). A significant improvement in the mechanical compressive properties was achieved (strength of ~2000 MPa, strain of ~40%) after annealing (at 1000 °C for 0.5 h) and oil-quenching. With its extremely high specific compressive strength (452 MPa·g/cm3) and ductility, the lightweight Al50Ti20Cr10Mn15V5 MEA demonstrates good potential for energy or transportation applications in the future.

A new infinite solid solution strategy to design eutectic high entropy alloys with B2 and BCC structure

2021 ◽  
Vol 199 ◽  
pp. 113886
Author(s):  
Xicong Ye ◽  
Jinyan Xiong ◽  
Xin Wu ◽  
Chang Liu ◽  
Dong Xu ◽  
...  
Keyword(s):  
Solid Solution ◽  
High Entropy Alloys ◽  
Solution Strategy ◽  
High Entropy ◽  
Bcc Structure

scholarly journals Vacuum brazing of Al2O3 and 3D printed Ti6Al4V lap-joints using high entropy driven AlZnCuFeSi filler

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ashutosh Sharma ◽  
Byungmin Ahn
Keyword(s):  
Strength Properties ◽  
Lap Joints ◽  
High Entropy Alloy ◽  
Face Centered Cubic ◽  
High Entropy ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
3D Printed ◽  
Face Centered ◽  
Alloy Filler

AbstractIn this work, we studied the brazing characteristics of Al2O3 and 3D printed Ti–6Al–4V alloys using a novel equiatomic AlZnCuFeSi high entropy alloy filler (HEAF). The HEAF was prepared by mechanical alloying of the constituent powder and spark plasma sintering (SPS) approach. The filler microstructure, wettability and melting point were investigated. The mechanical and joint strength properties were also evaluated. The results showed that the developed AlZnCuFeSi HEAF consists of a dual phase (Cu–Zn, face-centered cubic (FCC)) and Al–Fe–Si rich (base centered cubic, BCC) phases. The phase structure of the (Cu–Al + Ti–Fe–Si)/solid solution promises a robust joint between Al2O3 and Ti–6Al–4V. In addition, the joint interfacial reaction was found to be modulated by the brazing temperature and time because of the altered activity of Ti and Zn. The optimum shear strength reached 84 MPa when the joint was brazed at 1050 °C for 60 s. The results can be promising for the integration of completely different materials using the entropy driven fillers developed in this study.

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