Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
4.2
2.4
Journals
Crystals
Special Issues
High-Performance Heterogeneous Nanostructured Materials
share announcement

High-Performance Heterogeneous Nanostructured Materials

A special issue of Crystals (ISSN 2073-4352). This special issue belongs to the section "Crystalline Metals and Alloys".

Deadline for manuscript submissions: closed (15 March 2022) | Viewed by 9848

Special Issue Editors

Dr. Xusheng Yang

E-Mail Website
Guest Editor
State Key Laboratory of Ultra-precision Machining Technology, Advanced Manufacturing Technology Research Centre, Department of Industrial and Systems Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China
Interests: heterogeneous nanostructured materials; Martensitic phase transformation; severe plastic deformation techniques; laser treatment/additive manufacturing; ultra-precision machining technology; HRTEM and In-situ HRTEM; high-entropy alloys
Special Issues, Collections and Topics in MDPI journals
Dr. Honghui Wu

E-Mail Website
Guest Editor
School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China
Interests: high strength and toughness of advanced metal materials; integrated calculation of metal material structure-property correlation; materials genome engineering
Special Issues, Collections and Topics in MDPI journals
Prof. Dr. Jiaming Zhu

E-Mail Website
Guest Editor
School of Civil Engineering, Shandong University, Jinan 250061, China
Interests: concentration gradient engineering; elastic engineering; smart materials; solid–solid phase transition; phase field modeling; relationship between microstructure and mechanical properties

Special Issue Information

Dear Colleagues,

A variety of key fields (including aerospace, advanced manufacturing, new energy, deep-sea technology, and transportation, etc.,) have created an urgent need for the design, fabrication, and service evaluation of new high-performance metallic structural materials. Uniformly reducing the grain size to the nanometer scale has been well recognized to substantially improve the strength of metals. However, the strengthened homogeneous nanograined metals will inevitably sacrifice other properties to a significant extent, such as ductility and thermal stability. In recent years, a new class of nanomaterials called heterogeneous nanostructured materials possessing the soft and hard mixed regions have been designed to a unique architecture, e.g., gradient phases/composition/grain size/twin spacing/lamellar, hierarchically structural grains/twins, and nanoprecipitates/second phases, from the nanometer scale to the macroscale in bulk specimens. Owing to the particular cooperative effects of strain/stress partitioning between different domains, heterogeneous structures can harvest the high strength from the hard domains and the high ductility from the soft domains, thus leading to the high strength–ductility synergy. Since some pioneering works (such as from Lu’s, Zhu’s, and Wu’s groups) reported in Nature and Science, heterogeneous nanostructured materials have been proven to effectively achieve high-performance mechanical properties, e.g., strength–ductility synergy, excellent strain hardening, enhanced resistance of fatigue, creep, and wear, and remarkable mechanical and thermal stabilities. In addition to the unprecedented mechanical properties, the heterogamous nanostructuring strategy is also beneficial for developing various multifunctional materials.

The current Special Issue aims to summarize the state of the art of research progress of various high-performance heterogeneous nanostructured metals and alloys, including (i) mechanical properties (e.g., strength, ductility, fatigue, creep, phase transformation, and wear behaviors), (ii) advanced fabrication methods (e.g., severe plastic deformation techniques, laser treatment/additive manufacturing, machining technology, etc.), and (iii) microstructure characterizations responsible for the formation and underlying plastic deformation mechanisms. Research papers related to experiments, computational simulations/high-throughput computing, and theoretical modeling are all welcomed.

Dr. Xusheng Yang
Prof. Dr. Honghui Wu
Prof. Dr. Jiaming Zhu
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Crystals is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2100 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • heterogeneous nanostructured materials
  • gradient nanostructure/nanotwin
  • mechanical properties
  • strength–ductility synergy
  • plastic deformation
  • phase transformation
  • fatigue and creep
  • tribological properties
  • thermal stability
  • microstructure
  • computer simulations and modeling
  • severe plastic deformation techniques
  • laser treatment/additive manufacturing
  • ultra-precision machining technology

Published Papers (5 papers)

Download All Papers
Order results
Result details
Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:

Research

Jump to: Review

15 pages, 4659 KiB  
Article
Grain Boundary Wetting Transition in the Mg-Based ZEK 100 Alloy
by Boris Straumal, Natalya Khrapova, Aleksandr Druzhinin, Kristina Tsoy, Gregory Davdian, Valery Orlov, Gregory Gerstein and Alexander Straumal
Crystals 2023, 13(11), 1538; https://doi.org/10.3390/cryst13111538 - 26 Oct 2023
Cited by 19 | Viewed by 1076
Abstract
Modern magnesium-based alloys are broadly used in various industries as well as for biodegradable medical implants due to their exceptional combination of light weight, strength, and plasticity. The studied ZEK100 alloy had a nominal composition of 1 wt.% zinc, 0.1 wt.% zirconium, and [...] Read more.
Modern magnesium-based alloys are broadly used in various industries as well as for biodegradable medical implants due to their exceptional combination of light weight, strength, and plasticity. The studied ZEK100 alloy had a nominal composition of 1 wt.% zinc, 0.1 wt.% zirconium, and 0.1 wt.% rare earth metals (REMs) such as Y, Ce, Nd, and La, with the remainder being Mg. It has been observed that between the solidus (Ts = 529.5 ± 0.5 °C) and liquidus temperature (Tl = 645 ± 5 °C), the Mg/Mg grain boundaries can contain either the droplets of a melt (incomplete or partial wetting) or the continuous liquid layers separating the abutting Mg grains (complete wetting). With the temperature increasing from Ts to Tl, the transformation proceeds from incomplete to complete grain boundary wetting. Below 565 °C, all grain boundaries are partially wetted by the melt. Above 565 °C, the completely wetted Mg/Mg grain boundaries appear. Their portion grows quickly with an increasing temperature until reaching 100% at 622 °C. Above 622 °C, all the solid Mg grains are completely surrounded by the melt. After rapid solidification, the REM-rich melt forms brittle intermetallic compounds. The compression strength as well as the compression yield strength parameter σ02 strongly depend on the morphology of the grain boundary layers. If the hard and brittle intermetallic phase has the shape of separated particles (partial wetting), the overall compression strength is about 341 MPa and σ02 = 101 MPa. If the polycrystal contains the continous intergarnular layers of the brittle intermetallic phase (complete wetting), the overall compression strength drops to 247 Mpa and σ02 to 40 Mpa. We for the first time observed, therefore, that the grain boundary wetting phenomena can strongly influence the mechanical properties of a polycrystal. Therefore, grain boundary wetting can be used for tailoring the behavior of materials. Full article
(This article belongs to the Special Issue High-Performance Heterogeneous Nanostructured Materials)
►▼ Show Figures

Figure 1

9 pages, 32410 KiB  
Article
Elastic Moduli and Mechanical Properties of Mo5SiB2 Single Crystals in the Mo-Si-B System
by Kunming Pan, Chengyang Zhang, Gaogao Dong, Rui Wang, Hua Yu, Changji Wang and Yongpeng Ren
Crystals 2022, 12(11), 1577; https://doi.org/10.3390/cryst12111577 - 4 Nov 2022
Viewed by 1197
Abstract
With outstanding high-temperature properties, the intermetallic Mo5SiB2 alloy is regarded as an extremely competitive ultra-temperature structural material. The maximum Young’s modulus of 398.0 GPa for single Mo5SiB2 crystals was found to be at the vertex of the [...] Read more.
With outstanding high-temperature properties, the intermetallic Mo5SiB2 alloy is regarded as an extremely competitive ultra-temperature structural material. The maximum Young’s modulus of 398.0 GPa for single Mo5SiB2 crystals was found to be at the vertex of the [010] direction, while the minimum value of 264.0 GPa was found in the [001] direction. For hardness, the maximum value was 451.7 HV after compression at 1200 °C in the radial direction, while the maximum hardness was 437.2 HV at 1300 °C in the axial direction of {111}<110>, showing obvious anisotropy. Under compression, the flow stresses rapidly increased and then decreased with the increase in strain, corresponding to the two different stages of work hardening and softening. An EBSD test showed that the grain orientation remained the same at different rates, but the texture was different. After high-temperature compression, the crystal underwent plastic deformation, dislocations slipped along the slip plane, and the grain rotated, so the grain texture changed from {111}<110> to {001}<110>. Full article
(This article belongs to the Special Issue High-Performance Heterogeneous Nanostructured Materials)
►▼ Show Figures

Figure 1

12 pages, 7647 KiB  
Article
Effect of Cr Content on the Microstructure of Casting Infiltration Layers: Simulations and Experiments
by Chong Chen, Tao Wang, Shizhong Wei, Wenliang Liu, Guoshang Zhang, Ying Tang, Kunming Pan, Long You, Liujie Xu and Tao Jiang
Crystals 2022, 12(8), 1022; https://doi.org/10.3390/cryst12081022 - 22 Jul 2022
Cited by 3 | Viewed by 1371
Abstract
High chromium cast irons are commonly used as casting infiltration layers in the applications of wear resistance. The formation mechanism of the casting infiltration layer is essential to better develop the surface wear resistance materials using the casting infiltration method. In the present [...] Read more.
High chromium cast irons are commonly used as casting infiltration layers in the applications of wear resistance. The formation mechanism of the casting infiltration layer is essential to better develop the surface wear resistance materials using the casting infiltration method. In the present work, casting infiltration layers with various Cr contents were fabricated in situ on the surface of parent ZG45 steel. CALPHAD-type calculations using Thermo-Calc software, SEM, EDS and microhardness tests were performed to study the effect of Cr on the microstructure and hardness of casting infiltration layers. All the microstructures of casting infiltration layers were composed of pearlite matrix and eutectic M7C3 carbide. With the increase in Cr content from 7.01 wt.% to 17.20 wt.%, the amount of M7C3 carbide increased from 5.05 vol.% to 13.12 vol.%, resulting in the increment of microhardness. With the aid of simulations, the solidification behavior and formation mechanism of casting infiltration layers were revealed. Full article
(This article belongs to the Special Issue High-Performance Heterogeneous Nanostructured Materials)
►▼ Show Figures

Figure 1

15 pages, 4537 KiB  
Article
Selective Laser Melting of Pure Ag and 925Ag Alloy and Their Thermal Conductivity
by Di Wang, Yang Wei, Xiongmian Wei, Khashayar Khanlari, Zhi Wang, Yongwei Feng and Xusheng Yang
Crystals 2022, 12(4), 480; https://doi.org/10.3390/cryst12040480 - 31 Mar 2022
Cited by 4 | Viewed by 2180
Abstract
Due to the high reflectivity of Ag to infrared lasers, there is little research focused on the manufacturing of Ag and Ag alloys by selective laser melting (SLM) technique. In this paper, the manufacturing characteristics, microstructure, and thermal conductivity of SLMed Ag, 925Ag, [...] Read more.
Due to the high reflectivity of Ag to infrared lasers, there is little research focused on the manufacturing of Ag and Ag alloys by selective laser melting (SLM) technique. In this paper, the manufacturing characteristics, microstructure, and thermal conductivity of SLMed Ag, 925Ag, and their heat-treated parts were studied. With the suitable processing parameters, Ag and 925Ag samples with relative densities of 91.06% and 96.56%, respectively, were obtained. Due to the existence of non-molten particles inside the samples and local high energy density of the laser during the processing, a large number of irregular pores and micropores were formed in the microstructures. XRD analysis shows that no phase transition occurred in the annealed Ag and solution-treated 925Ag parts, as compared to their as-built conditions. The SLMed Ag exhibited fine equiaxed grains, while both columnar grains and elongated lath grains existed in the SLMed 925Ag parts. The annealed Ag and solution-treated 925Ag exhibited large equiaxed grains. Due to the grain growth that occurred in the microstructure, the thermal conductivity of Ag increased by 11.35% after completing the annealing treatment. However, that of 925Ag decreased by 17.14% after completing the solid solution treatment, due to the precipitation of the strengthening phase at grain boundaries. A comparison of the thermal conductivities of Ag and 925Ag shows that the influence of the materials on the obtained thermal conductivities was more pronounced than that of the porosity. Full article
(This article belongs to the Special Issue High-Performance Heterogeneous Nanostructured Materials)
►▼ Show Figures

Figure 1

Review

Jump to: Research

20 pages, 10639 KiB  
Review
Severe Plastic Deformation and Phase Transformations in High Entropy Alloys: A Review
by Boris B. Straumal, Roman Kulagin, Brigitte Baretzky, Natalia Yu. Anisimova, Mikhail V. Kiselevskiy, Leonid Klinger, Petr B. Straumal, Olga A. Kogtenkova and Ruslan Z. Valiev
Crystals 2022, 12(1), 54; https://doi.org/10.3390/cryst12010054 - 31 Dec 2021
Cited by 16 | Viewed by 3083
Abstract
This review discusses an area of expertise that is at the intersection of three large parts of materials science. These are phase transformations, severe plastic deformation (SPD), and high-entropy alloys (HEA). First, SPD makes it possible to determine the borders of single-phase regions [...] Read more.
This review discusses an area of expertise that is at the intersection of three large parts of materials science. These are phase transformations, severe plastic deformation (SPD), and high-entropy alloys (HEA). First, SPD makes it possible to determine the borders of single-phase regions of existence of a multicomponent solid solution in HEAs. An important feature of SPD is that using these technologies, it is possible to obtain second-phase nanoparticles included in a matrix with a grain size of several tens of nanometers. Such materials have a very high specific density of internal boundaries. These boundaries serve as pathways for accelerated diffusion. As a result of the annealing of HEAs subjected to SPD, it is possible to accurately determine the border temperature of a single-phase solid solution area on the multicomponent phase diagram of the HEA. Secondly, SPD itself induces phase transformations in HEAs. Among these transformations is the decomposition of a single-phase solid solution with the formation of nanoparticles of the second phase, the formation of high-pressure phases, amorphization, as well as spinodal decomposition. Thirdly, during SPD, a large number of new grain boundaries (GBs) are formed due to the crystallites refinement. Segregation layers exist at these new GBs. The concentration of the components in GBs differs from that in the bulk solid solution. As a result of the formation of a large number of new GBs, atoms leave the bulk solution and form segregation layers. Thus, the composition of the solid solution in the volume also changes. All these processes make it possible to purposefully influence the composition, structure and useful properties of HEAs, especially for medical applications. Full article
(This article belongs to the Special Issue High-Performance Heterogeneous Nanostructured Materials)
►▼ Show Figures

Figure 1

Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:
 
Displaying articles 1-5
Back to TopTop