scholarly journals Gradient and lamellar heterostructures for superior mechanical properties

MRS Bulletin ◽  
2021 ◽  
Vol 46 (3) ◽  
pp. 244-249 ◽  
Author(s):  
Xiaolei Wu ◽  
Yuntian Zhu
Keyword(s):  
Mechanical Properties ◽  
Synergistic Effect ◽  
Tensile Deformation ◽  
Back Stress ◽  
Mechanical Behaviors ◽  
Dramatic Difference ◽  
Superior Mechanical Properties ◽  
Heterogeneous Deformation ◽  
The Relationship ◽  
Size Gradient

AbstractHeterostructured (HS) materials are a novel class of materials with mechanical properties that are superior over their conventional homogeneous counterparts. They are composed of HS zones with a dramatic difference in mechanical behaviors, which produces a synergistic effect on mechanical properties that are above the prediction by the rule-of-mixtures. Among all heterostructures, the two most studied are grain-size gradient structure and heterolamellar structure. These two heterostructures produce typical heterogeneous deformation during tensile deformation, producing long-range back stress in the soft zones and forward stress in the hard zones, which collectively produces hetero deformation-induced (HDI) stress to enhance the yield strength before yielding, and HDI hardening after yielding to retain ductility. In this article, we will focus on these two types of heterostructures. The issues, concerns, and progress are reviewed with the emphasis on the synergistic effect of mechanical properties, the fundamentals of several special plastic behaviors (e.g., strain gradient, HDI hardening and strain hardening), the plastic deformation mechanism, and the relationship between the microstructure and properties.

scholarly journals Synergistic effect of CB and GO/CNT hybrid fillers on the mechanical properties and fatigue behavior of NR composites

RSC Advances ◽  
2018 ◽  
Vol 8 (19) ◽  
pp. 10573-10581 ◽  
Author(s):  
Laiyun Wei ◽  
Xuan Fu ◽  
Mingchao Luo ◽  
Zhengtian Xie ◽  
Cheng Huang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Graphene Oxide ◽  
Carbon Nanotube ◽  
Carbon Black ◽  
Synergistic Effect ◽  
Fatigue Behavior ◽  
Crack Growth Resistance ◽  
Hybrid Fillers ◽  
Superior Mechanical Properties ◽  
Heat Build Up

Graphene oxide (GO) and carbon nanotube (CNT) hybrid fillers were used to replace partial carbon black (CB), and GO/CNT/CB/NR composites were prepared with excellent crack growth resistance, low heat build-up and superior mechanical properties.

scholarly journals Helium Effects on the Mechanical Properties of Nanocrystalline Fe: Based on Molecular Dynamics

Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 532
Author(s):  
Chunping Xu ◽  
Dongyan Yang
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Lattice Distortion ◽  
Tensile Deformation ◽  
Peak Stress ◽  
X Ray Diffraction ◽  
Peak Separation ◽  
Tensile Process ◽  
Xrd Patterns ◽  
The Relationship

A molecular dynamics (MD) simulation study was performed to investigate the effects of helium (He) on the mechanical properties of nanocrystalline body-centered cubic iron (BCC Fe). Simulated X-ray diffraction (XRD) was used to explore the relationship between the generation of cracks and the change of the crystal structure in nanocrystalline BCC Fe during tensile deformation. It is observed that the peak stress and the elastic modulus decrease with increasing concentration of He atoms, which are introduced into the grain boundary (GB) region of nanocrystalline Fe. The generation and connection of intergranular cracks are enhanced by He atoms. Significant peak separation, which is associated with the generation of cracks, is found in the simulated XRD patterns of nanocrystalline Fe during the tensile process. The lower diffraction angle of the {211}′ peak suggests a more serious lattice distortion during loading. For all nanocrystalline Fe deformed to 6% strain, the degree and fraction of the lattice distortion increases with the increasing loading stress.

Serration and Reversion Treatment in Al-Zn Alloys

2014 ◽  
Vol 794-796 ◽  
pp. 1175-1180
Author(s):  
Teruto Kanadani ◽  
Norihito Nagata ◽  
Keiyu Nakagawa ◽  
Makoto Hino ◽  
Koji Murakami
Keyword(s):  
Mechanical Properties ◽  
Annealing Temperature ◽  
Tensile Deformation ◽  
Stress Amplitude ◽  
Strain Curve ◽  
Stress Strain Curve ◽  
The One ◽  
Aging Phenomena ◽  
The Relationship ◽  
Zn Alloys

Aging phenomena of Al-Zn alloys have been much investigated and many studies have been made on the change of mechanical properties on aging. Appearance of saw-tooth yielding (serration) in the stress-strain curve of tensile deformation has been reported in several reports. In this study, the relationship between occurrence of serration and reversion heat treatment was studied by tensile test on Al-Zn alloys. Serration was observed for the furnace cooled specimen, but not for the as-quenched one and the shortly aged one, which result is difficult to be interpreted by the Cottrell theory. The stress amplitude in the serration increased with increasing the time of annealing for reversion and then stayed at a constant value which might be interpreted by the Cottrell theory. The stress amplitude in the serration decreased with increasing the annealing temperature, which is contrary to the prediction by the Cottrell theory. The specimen directly annealed without aging and the one annealed after aging agreed well with each other in the tensile strength and the stress amplitude in the serration, which suggests solute clusters as the cause of serration.

Hydrogels with superior mechanical properties from the synergistic effect in hydrophobic–hydrophilic copolymers

2019 ◽  
Vol 362 ◽  
pp. 325-338 ◽  
Author(s):  
Md. Tariful Islam Mredha ◽  
Suraj Kumar Pathak ◽  
Van Tron Tran ◽  
Jiaxi Cui ◽  
Insu Jeon
Keyword(s):  
Mechanical Properties ◽  
Synergistic Effect ◽  
Superior Mechanical Properties

scholarly journals A Review on Heterogeneous Nanostructures: A Strategy for Superior Mechanical Properties in Metals

Metals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 598 ◽  
Author(s):  
Yan Ma ◽  
Muxin Yang ◽  
Fuping Yuan ◽  
Xiaolei Wu
Keyword(s):  
Mechanical Properties ◽  
High Strength ◽  
Back Stress ◽  
Coarse Grained ◽  
Strain Partitioning ◽  
Challenges And Opportunities ◽  
New Strategy ◽  
Future Challenges ◽  
Superior Mechanical Properties ◽  
Strength And Ductility

Generally, strength and ductility are mutually exclusive in homogeneous metals. Nanostructured metals can have much higher strength when compared to their coarse-grained counterparts, while simple microstructure refinement to nanoscale generally results in poor strain hardening and limited ductility. In recent years, heterogeneous nanostructures in metals have been proven to be a new strategy to achieve unprecedented mechanical properties that are not accessible to their homogeneous counterparts. Here, we review recent advances in overcoming this strength–ductility trade-off by the designs of several heterogeneous nanostructures in metals: heterogeneous grain/lamellar/phase structures, gradient structure, nanotwinned structure and structure with nanoprecipitates. These structural heterogeneities can induce stress/strain partitioning between domains with dramatically different strengths, strain gradients and geometrically necessary dislocations near domain interfaces, and back-stress strengthening/hardening for high strength and large ductility. This review also provides the guideline for optimizing the mechanical properties in heterogeneous nanostructures by highlighting future challenges and opportunities.

Mechanical Behaviors of Ultrafine Grained Metallic Materials

2007 ◽  
Vol 124-126 ◽  
pp. 1325-1328
Author(s):  
Dong Hyuk Shin ◽  
Duck Young Hwang ◽  
Jung Yong Ahn ◽  
Kyung Tae Park ◽  
Yong Suk Kim ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Coarse Grained ◽  
Metallic Materials ◽  
Room Temperature Ductility ◽  
Ultrafine Grained ◽  
Superior Mechanical Properties ◽  
Ultrafine Grained Materials ◽  
The Relationship

Ultrafine grained materials fabricated by severe plastic deformation exhibit both superior and inferior mechanical properties, as the prominent structural materials, compared to coarse grained counterparts. The superior mechanical properties are ultrahigh strength and exceptional ductility at high temperatures (i.e., superplasticity). The inferior mechanical properties are lack of strain hardenability and room temperature ductility. In this study, the relationship between microstructure and mechanical properties of ultrafine grained materials fabricated by severe plastic deformation is investigated in order to provide insight broadening their future applicability.

Microstructure and Mechanical Properties of Zr-Co-Ni Intermetallic Compound

2010 ◽  
Vol 638-642 ◽  
pp. 1379-1383 ◽  
Author(s):  
Mitsuhiro Matsuda ◽  
Katsutoshi Hayashi ◽  
Minoru Nishida
Keyword(s):  
Mechanical Properties ◽  
Room Temperature ◽  
Tensile Deformation ◽  
Tensile Ductility ◽  
Parent Phase ◽  
Transformation Induced Plasticity ◽  
Remarkable Improvement ◽  
Microstructure And Mechanical Properties ◽  
The Relationship ◽  
High Plastic

The relationship between the microstructure and mechanical properties on the ternary ZrCoNi alloys has been investigated. Zr50Co50-xNix alloys undergo martensitic transformation from the B2 to B33 structure by the substitution of Ni for Co. The tensile ductility at room temperature increases remarkably without the loss of yield strength by substituting Ni. Zr50Co39Ni11 alloy has the extremely high plastic elongation of 21%. There are many {021}B33 deformation twins in the B2 parent phase just near the tensile fractured area. These twins are the strain induced martensitic phase due to the tensile deformation. Consequently, the remarkable improvement of the ductility of ZrCoNi alloys is due to the transformation induced plasticity.

Study on Mechanical Behaviors of New Reinforced Concrete Hollow Floor Slab

2011 ◽  
Vol 94-96 ◽  
pp. 1018-1021
Author(s):  
Xin Zhao ◽  
Dan Dan Kong ◽  
Zhi Wei Zhang ◽  
Mai Wu
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Reinforced Concrete ◽  
The Other ◽  
Mechanical Behaviors ◽  
Floor Slab ◽  
Study Results ◽  
Superior Mechanical Properties ◽  
New Type

In this paper a new type of reinforced concrete four-way rib hollow slab was proposed by the authors first. Further in order to research on the mechanical properties of the new floor slab the other two common slabs were compared with the new one, that was two-way rib hollow slab and solid slab. The rational finite element (FE) models of the three kinds of slabs supported by four corner columns were built up respectively by ANSYS. The deflection and stress of the three kinds of slabs under three load cases were calculated separately, on the basis of which thorough comparisons and analysis were carried out. The study results showed that the new reinforced concrete four-way rib hollow floor slab has superior mechanical properties.

scholarly journals Structure and tribocorrosion behavior of CrMoSiCN nanocomposite coating with low C content in artificial seawater

Friction ◽  
2020 ◽  
Author(s):  
Yongqiang Fu ◽  
Fei Zhou ◽  
Maoda Zhang ◽  
Qianzhi Wang ◽  
Zhifeng Zhou
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Synergistic Effect ◽  
Nanocomposite Coating ◽  
Open Circuit ◽  
Strengthening Effect ◽  
Material Loss ◽  
Solid Solution Strengthening ◽  
Unbalanced Magnetron ◽  
Superior Mechanical Properties

AbstractCrMoSiCN nanocomposite coatings with a low C content were prepared on Ti-6Al-4V using an unbalanced magnetron sputtering system, and their corresponding microstructures, mechanical properties, and tribocorrosion performance were evaluated in detail. The results revealed that the CrMoSiCN coating had a compact nanocomposite microstructure consisting of CrN and Mo2N nanocrystallites, (Cr, Mo)N solid solution, and Si-C-N amorphous phases. Moreover, the coating exhibited superior mechanical properties with a hardness of 28.6 GPa and an elastic modulus of 273 GPa, owing to the solid solution strengthening effect. The tribocorrosion test results showed that the dominant failure of the Ti-6Al-4V alloy was caused by the corrosion contribution to wear behaviors (synergistic effect). The CrMoSiCN nanocomposite coating could effectively alleviate the material loss caused by the synergistic effect of corrosion and wear behaviors, leading to pure wear behaviors during the entire tribocorrosion process. The corresponding tribocorrosion mechanisms under the open circuit potential and dynamic polarization conditions were discussed in terms of their tribocorrosion behaviors.

scholarly journals Mechanical Properties and Deformation Mechanisms of Heterostructured High-Entropy and Medium-Entropy Alloys: A Review

2022 ◽  
Vol 8 ◽  
Author(s):  
Wei Jiang ◽  
Yuntian Zhu ◽  
Yonghao Zhao
Keyword(s):  
Mechanical Properties ◽  
Review Paper ◽  
Back Stress ◽  
Industrial Applications ◽  
Deformation Mechanisms ◽  
High Entropy Alloys ◽  
High Entropy ◽  
The World ◽  
Superior Mechanical Properties ◽  
Principal Elements

Recently, heterostructured (HS) materials, consisting of hard and soft zones with dramatically different strengths, have been developed and received extensive attention because they have been reported to exhibit superior mechanical properties over those predicted by the rule of mixtures. Due to the accumulation of geometrically necessary dislocations during plastic deformation, a back stress is developed in the soft zones to increase the yield strength of HS materials, which also induce forward stress in the hard zones, and a global hetero-deformation induced (HDI) hardening to retain ductility. High-entropy alloys (HEAs) and medium-entropy alloys (MEAs) or multicomponent alloys usually contain three or more principal elements in near-equal atomic ratios and have been widely studied in the world. This review paper first introduces concepts of HS materials and HEAs/MEAs, respectively, and then reviewed emphatically the mechanical properties and deformation mechanisms of HS HEAs/MEAs. Finally, we discuss the prospect for industrial applications of the HS HEAs and MEAs.

Sign in / Sign up

Export Citation Format

Share Document