Microstructure and mechanical properties of AlCrFeCoNi high-entropy alloy particle reinforced Mg-9Al-1Zn matrix composites

2021 ◽  
Vol 112 (7) ◽  
pp. 538-545
Author(s):  
Yongsheng Chen ◽  
Zesheng Ji ◽  
Maoliang Hu ◽  
Hongyu Xu ◽  
Guangjie Feng
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Volume Fraction ◽  
Dominant Role ◽  
Particle Volume Fraction ◽  
Stress Transfer ◽  
High Entropy Alloy ◽  
Compression Tests ◽  
Particle Volume ◽  
High Entropy

Abstract AlCrFeCoNi particles were added to Mg-9Al-1Zn alloy in a rotary blowing process. The microstructures and mechanical properties of Mg-9Al-1Zn based composites were characterized by means of X-ray diffraction, optical microscopy, scanning electron microscopy, transmission electron microscopy, and tensile and compression tests at room temperature. Results revealed that AlCrFeCoNi particles could effectively refine the grains, and the rotary blowing process enabled the uniform distribution of these particles. The mechanical properties of composites improved with the increase of particle volume fraction. The superior wettability of AlCrFeCoNi particles supported their reliable bonding with the Mg-9Al-1Zn matrix. The Hall–Petch strengthening and stress transfer effect played a dominant role in the improvement of compressive and tensile properties.

scholarly journals Effects of Silicon Content on the Microstructures and Mechanical Properties of (AlCrTiZrV)-Six-N High-Entropy Alloy Films

Entropy ◽  
2019 ◽  
Vol 21 (1) ◽  
pp. 75 ◽  
Author(s):  
Jingrui Niu ◽  
Wei Li ◽  
Ping Liu ◽  
Ke Zhang ◽  
Fengcang Ma ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Amorphous Phase ◽  
Silicon Content ◽  
High Entropy Alloy ◽  
Strengthening Effect ◽  
Nanocomposite Structure ◽  
High Entropy ◽  
Nanocrystalline Structures ◽  
Microstructures And Mechanical Properties

A series of (AlCrTiZrV)-Six-N films with different silicon contents were deposited on monocrystalline silicon substrates by direct-current (DC) magnetron sputtering. The films were characterized by the X-ray diffractometry (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), and nano-indentation techniques. The effects of the silicon content on the microstructures and mechanical properties of the films were investigated. The experimental results show that the (AlCrTiZrV)N films grow in columnar grains and present a (200) preferential growth orientation. The addition of the silicon element leads to the disappearance of the (200) peak, and the grain refinement of the (AlCrTiZrV)-Six-N films. Meanwhile, the reticular amorphous phase is formed, thus developing the nanocomposite structure with the nanocrystalline structures encapsulated by the amorphous phase. With the increase of the silicon content, the mechanical properties first increase and then decrease. The maximal hardness and modulus of the film reach 34.3 GPa and 301.5 GPa, respectively, with the silicon content (x) of 8% (volume percent). The strengthening effect of the (AlCrTiZrV)-Six-N film can be mainly attributed to the formation of the nanocomposite structure.

scholarly journals Effects of Nb Addition on Microstructures and Mechanical Properties of Nbx-CoCrFeMnNi High Entropy Alloy Films

Coatings ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1539
Author(s):  
Yu-Hsuan Liang ◽  
Chia-Lin Li ◽  
Chun-Hway Hsueh
Keyword(s):  
Mechanical Properties ◽  
Amorphous Phase ◽  
Compressive Yield Strength ◽  
High Entropy Alloy ◽  
Face Centered Cubic ◽  
Compression Tests ◽  
Alloy Films ◽  
High Entropy ◽  
Microstructures And Mechanical Properties ◽  
Nb Addition

In the present work, Nbx-CoCrFeMnNi high entropy alloy films (HEAFs, 0 to 7.2 at.% Nb) were fabricated by radio frequency (RF) magnetron co-sputtering of CoCrFeMnNi alloy and Nb targets. The effects of Nb addition on the microstructures and mechanical properties of HEAFs were systematically investigated. For Nb-free film (0 at.% Nb), the face-centered cubic (FCC) peaks were identified in the X-ray diffraction (XRD) pattern. The addition of Nb resulted in a broadening of diffraction peaks, a decrease in peak intensity, and the vanishment of high-angle peaks. Transmission electron microscope (TEM) images indicated the formation of nanotwins at low Nb concentrations, and a transition from a single phase FCC solid solution to an amorphous phase was observed with the increasing Nb concentration. The films were strengthened with an increase in Nb concentration. Specifically, the hardness characterized by nanoindentation increased from 6.5 to 8.1 GPa. The compressive yield strength and fracture strength measured from micropillar compression tests were improved from 1.08 GPs and 2.56 GPa to 2.70 GPa and 5.76 GPa, respectively, whereas the fracture strain decreased from >29.4% (no fracture) to 15.8%. Additionally, shear banding was observed in the presence of amorphous phase.

scholarly journals Effects of Annealing on Microstructure and Mechanical Properties of Metastable Powder Metallurgy CoCrFeNiMo0.2 High Entropy Alloy

Entropy ◽  
2019 ◽  
Vol 21 (5) ◽  
pp. 448 ◽  
Author(s):  
Cui Zhang ◽  
Bin Liu ◽  
Yong Liu ◽  
Qihong Fang ◽  
Wenmin Guo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Powder Metallurgy ◽  
Volume Fraction ◽  
High Entropy Alloy ◽  
High Entropy ◽  
Large Volume Fraction ◽  
The Matrix ◽  
Coarse Precipitation ◽  
Precipitation Enhancement ◽  
Precipitation Phase

A CoCrFeNiMo0.2 high entropy alloy (HEA) was prepared through powder metallurgy (P/M) process. The effects of annealing on microstructural evolution and mechanical properties of P/M HEAs were investigated. The results show that the P/M HEA exhibit a metastable FCC single-phase structure. Subsequently, annealing causes precipitation in the grains and at the grain boundaries simultaneously. As the temperature increases, the size of the precipitates grows, while the content of the precipitates tends to increase gradually first, and then decrease as the annealing temperature goes up to 1000 °C. As the annealing time is prolonged, the size and content of the precipitates gradually increases, eventually reaching a saturated stable value. The mechanical properties of the annealed alloys have a significant correspondence with the precipitation behavior. The larger the volume fraction and the size of the precipitates, the higher the strength and the lower the plasticity of the HEA. The CoCrFeNiMo0.2 high entropy alloy, which annealed at 800 °C for 72 h, exhibited the most excellent mechanical properties with the ultimate tensile strength of about 850 MPa and an elongation of about 30%. Nearly all of the annealed HEAs exhibit good strength–ductility combinations due to the significant precipitation enhancement and nanotwinning. The separation of the coarse precipitation phase and the matrix during the deformation process is the main reason for the formation of micropores. Formation of large volume fraction of micropores results in a decrease in the plasticity of the alloy.

Microstructure and Mechanical Properties of Metal Injection Molded SiCP/ Cu Composites

2012 ◽  
Vol 629 ◽  
pp. 105-109
Author(s):  
Yi Qiang He ◽  
Jian Ming Yang ◽  
Bin Qiao ◽  
Li Chao Feng
Keyword(s):  
Mechanical Properties ◽  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Metal Injection Molding ◽  
Injection Molding Process ◽  
Molding Process ◽  
Particle Volume ◽  
Sic Particles ◽  
The Matrix ◽  
Fraction Increase

SiCP/Cu composite was prepared by metal injection molding process. Microstructure, mechanical properties, fracture surface, and wear resistance of SiCP/Cu composite were investigated in this study. The research results show that SiCP/Cu were sintered sucessfully by the sintering process with hydrogen protection and high temperature of 1050°C. The tensile strength of the composites depends on the fraction and distribution of SiC particles which is resulted from microcracks nucleate in the matrix between SiC particles because of SiC particle aggregation. The tensile strengths of 5vol.%, 10vol.%, and15vol.%SiCP/Cu are 254MPa, 291MPa and 278MPa separately. SiC particles are contribute to enhance the abrasive resitance of the composite when particle volume fraction increase from 10% to 15%.

scholarly journals Evolution of Microstructure and Mechanical Properties of LM25–HEA Composite Processed through Stir Casting with a Bottom Pouring System

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 230
Author(s):  
Mekala Chinababu ◽  
Nandivelegu Naga Krishna ◽  
Katakam Sivaprasad ◽  
Konda Gokuldoss Prashanth ◽  
Eluri Bhaskara Rao
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Tensile Strength ◽  
Aluminum Matrix ◽  
Stir Casting ◽  
Significant Loss ◽  
Aluminum Matrix Composites ◽  
High Entropy Alloy ◽  
High Entropy ◽  
The Matrix

Aluminum matrix composites reinforced by CoCrFeMnNi high entropy alloy (HEA) particulates were fabricated using the stir casting process. The as-cast specimens were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and transmission electron microscopy (TEM). The results indicated that flake-like silicon particles and HEA particles were distributed uniformly in the aluminum matrix. TEM micrographs revealed the presence of both the matrix and reinforcement phases, and no intermetallic phases were formed at the interface of the matrix and reinforcement phases. The mechanical properties of hardness and tensile strength increased with an increase in the HEA content. The Al 6063–5 wt.% HEA composite had a ultimate tensile strength (UTS) of approximately 197 MPa with a reasonable ductility (around 4.05%). The LM25–5 wt.% HEA composite had a UTS of approximately 195 Mpa. However, the percent elongation decreased to roughly 3.80%. When the reinforcement content increased to 10 wt.% in the LM25 composite, the UTS reached 210 MPpa, and the elongation was confined to roughly 3.40%. The fracture morphology changed from dimple structures to cleavage planes on the fracture surface with HEA weight percentage enhancement. The LM25 alloy reinforced with HEA particles showed enhanced mechanical strength without a significant loss of ductility; this composite may find application in marine and ship building industries.

Microstructure and Mechanical Properties of High Strength Al2O3p/6061Al Composites

2007 ◽  
Vol 353-358 ◽  
pp. 1390-1393
Author(s):  
Bai Feng Luan ◽  
Gao Hui Wu ◽  
Qing Liu ◽  
Niels Hansen ◽  
Ting Quan Lei
Keyword(s):  
Mechanical Properties ◽  
Yield Stress ◽  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Hot Extrusion ◽  
High Strength ◽  
Dispersion Strengthening ◽  
Particle Volume ◽  
Microstructure And Mechanical Properties ◽  
Before And After

An experimental study of microstructure and mechanical properties in the Al2O3 particulate reinforced 6061 Aluminum composites has been used to determine the effect of extrusion and particle volume fraction (20, 26, 30, 40, 50, 60%Vf) in deformed metal matrix composites. The microstructure of Al2O3 /6061Al composite before and after hot extrusion is investigated by TEM and SEM. Results show that dislocation and subgrain generated after hot extrusion as well as the particle distribution of composite become more uniform with extrusion ratio of 10:1. The ultimate strength, yield strength and elongation of the composite also increase after hot extrusion. Dispersion strengthening and subgrain boundary strengthening is discussed and also the effect of precipitate introduced by heat treatment both after casting and after extrusion. The yield stress (0.2% offset) of the composites has been calculated and predicted using a standard dislocation hardening model. Whilst the correlation between this and the measured value of yield stress obtained in previous experimental test is reasonable.

Microstructure Refinement in the CoCrFeNiMn High Entropy Alloy under Plastic Straining

2016 ◽  
Vol 879 ◽  
pp. 1853-1858 ◽  
Author(s):  
Nikita Stepanov ◽  
Dmitry Shaysultanov ◽  
Nikita Yurchenko ◽  
Margarita Klimova ◽  
Sergey Zherebtsov ◽  
...  
Keyword(s):  
Yield Strength ◽  
Volume Fraction ◽  
Dominant Role ◽  
Mechanical Twinning ◽  
Cubic Phase ◽  
High Entropy Alloy ◽  
Face Centered Cubic ◽  
Cryogenic Temperatures ◽  
High Entropy ◽  
Average Grain Size

The effect of plastic deformation under various conditions of the equiatomic CoCrFeNiMn alloy with single face-centered cubic phase structure was studied. The alloy was rolled at room and cryogenic temperatures, and uniaxially compressed at room temperature and temperatures of 600-1100°C with different height reductions. In addition, multiaxial forging at 900-1000°C was performed. Scanning and transmission electron microscopy, including EBSD analysis, was widely employed to characterize microstructure of the deformed alloy. At room and cryogenic temperatures, mechanical twinning and shear banding plays play dominant role in microstructure evolution. Extensive refinement of the microstructure occurs as the result of rolling with reduction of 80%. During deformation at 600-1100°C, discontinuous dynamic recrystallization takes place. The recrystallized grains size and their volume fraction increases with increase of deformation temperature. Multiaxial forging at 900-1000°C was used to produce fully recrystallized structure with average grain size of 6.7 μm. The alloy in the initial condition had low yield strength of 160 Mpa but remarkable tensile ductility of 68%. Rolling substantial increases yield strength to 1120-1290 MPa, but results in loss of ductility. After multiaxial forging the alloy has balanced combination of properties – yield strength of 280 MPa and elongation of 56%.

Physical and mechanical properties of stir-casting processed AA2024/B4Cp composites

2014 ◽  
Vol 21 (4) ◽  
pp. 505-515 ◽  
Author(s):  
Aykut Canakci ◽  
Fazli Arslan ◽  
Temel Varol
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Tensile Strength ◽  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Stir Casting ◽  
Particle Volume ◽  
Electron Microscopic ◽  
Particle Content ◽  
Casting Technique

AbstractIn this study, metal matrix composites of an aluminum alloy (AA2024) and B4C particles with volume fractions 3, 5, 7, and 10 vol% and with sizes 29 and 71 μm were produced using stir-casting technique. The effects of B4C particle content and size of boron carbide on the mechanical properties of the composites such as hardness, 0.2% yield strength, tensile strength, and fracture were investigated. Furthermore, the relation between particle content, microstructure, and particle distribution has been investigated. The hardness of the composites increased with increasing particle volume fraction and with decreasing particle size, although the tensile strength of the composites decreased with increasing particle volume fraction and with decreasing particle size. Scanning electron microscopic observations of the microstructures revealed that dispersion of the coarser sizes of B4C particles was more uniform while the finer particles led to agglomeration of the particles and porosity.

Toughening Mechanism and Mechanical Properties Simulation of Rubber-Toughened Polymers

2016 ◽  
Vol 723 ◽  
pp. 68-73
Author(s):  
Hong Tu Song
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Poisson’S Ratio ◽  
Volume Fraction ◽  
Rubber Particle ◽  
Particle Volume Fraction ◽  
Poisson's Ratio ◽  
Toughening Mechanism ◽  
Particle Volume ◽  
Rubber Toughened

When blending rubbers into polymers, different rubber distribution status and fraction due to different mechanical property. In this research, effective mechanical properties of rubber-toughened polymers with four blending fraction in six kinds of particle distribution status are simulated numerically by using finite element method. Rubber particle distribution model include four 2D models and two 3D models. Typical effective mechanical properties such as yield stress, Young's modulus, Poisson's ratio and stress-strain curve of each status are obtained. The Results show that all models Young's modulus and Poisson's ratio decrease with rubber particle volume fraction increasing. Young's modulus and Poisson's ratio of three-dimensional body-centered cubic and face-centered cubic models are in a close magnitude range, it means rubber particle volume fraction has less effect on 2D models and two 3D models. As we all known, Matrix yielding, crazing and interface debond. All play an important role in the toughening process of rubber-toughened polymers. So in this paper we also study on toughening mechanism using same models. Our simulation takes use of stress concentration factor, yield ratio and interface elements' strain difference which is related with matrix yielding, crazing and interface debond to study the toughening mechanism. Simulation shows that the maximum stress concentration factor increases with particle volume fraction. The shear yielding occurs first at the equator of rubber particle, and then yield region expands from the equator to the pole of the particle with loads increasing.

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