On the thermodynamic relationship between nanocrystalline materials and glasses

Atom probe tomography provides compositional information in three dimensions at the atomic scale, and is therefore extremely suited to the study of nanocrystalline materials. In this paper we present atom probe results from the investigation of nanocomposite TiSi¬Nx coatings and nanocrystalline Al. We address some of the major challenges associated with the study of nanocrystalline materials, including specimen preparation, visualisation, common artefacts in the data and approaches to quantitative analysis. We also discuss the potential for the technique to relate crystallographic information to the compositional maps.

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Mechanical Properties of Nanocrystalline Materials Produced by In Situ Consolidation Ball Milling

Materials Science Forum ◽

10.4028/www.scientific.net/msf.579.15 ◽

2008 ◽

Vol 579 ◽

pp. 15-28 ◽

Cited By ~ 8

Author(s):

Carl C. Koch ◽

Khaled M. Youssef ◽

Ron O. Scattergood

Keyword(s):

Mechanical Properties ◽

Ball Milling ◽

Nanocrystalline Materials ◽

Preparation Method ◽

High Strength ◽

Al Alloys ◽

Ductile Metals ◽

Cu Alloys ◽

Bulk Nanocrystalline

This paper reviews a method, “in situ consolidation ball milling” that provides artifactfree bulk nanocrystalline samples for several ductile metals such as Zn, Al and Al alloys, and Cu and Cu alloys. The preparation method is described in this paper and examples of the mechanical behavior of nanocrystalline materials made by this technique are given. It is found that in such artifact-free metals, combinations of both high strength and good ductility are possible.

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Mechanochemical Synthesis and Rapid Consolidation of Nanocrystalline 3NiAl-Al2O3Composites

Journal of Nanomaterials ◽

10.1155/2011/793135 ◽

2011 ◽

Vol 2011 ◽

pp. 1-5 ◽

Cited By ~ 1

Author(s):

In-Jin Shon ◽

In-Yong Ko ◽

Seung-Hoon Jo ◽

Jung-Mann Doh ◽

Jin-Kook Yoon ◽

...

Keyword(s):

Mechanical Properties ◽

Fracture Toughness ◽

Mechanochemical Synthesis ◽

High Frequency ◽

Nanocrystalline Materials ◽

Physical And Mechanical Properties ◽

High Energy ◽

Reinforced Composite ◽

Energy Ball ◽

High Frequency Induction

Nanopowders of 3NiAl and Al2O3were synthesized from 3NiO and 5Al powders by high-energy ball milling. Nanocrystalline Al2O3reinforced composite was consolidated by high-frequency induction-heated sintering within 3 minutes from mechanochemically synthesized powders of Al2O3and 3NiAl. The advantage of this process is that it allows very quick densification to near theoretical density and inhibition grain growth. Nanocrystalline materials have received much attention as advanced engineering materials with improved physical and mechanical properties. The relative density of the composite was 97%. The average Vickers hardness and fracture toughness values obtained were 804 kg/mm2and 7.5 MPa⋅m1/2, respectively.

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The Role of Hydrogen on the Behavior of Intergranular Cracks in Bicrystalline α-Fe Nanowires

Nanomaterials ◽

10.3390/nano11020294 ◽

2021 ◽

Vol 11 (2) ◽

pp. 294

Author(s):

Jiaqing Li ◽

Cheng Lu ◽

Long Wang ◽

Linqing Pei ◽

Ajit Godbole ◽

...

Keyword(s):

Molecular Dynamics ◽

Nanocrystalline Materials ◽

Fracture Mechanisms ◽

Bulk Materials ◽

Cleavage Process ◽

Deformation And Fracture ◽

Dynamics Simulations ◽

Crack Trapping ◽

Cleavage Failure

Hydrogen embrittlement (HE) has been extensively studied in bulk materials. However, little is known about the role of H on the plastic deformation and fracture mechanisms of nanoscale materials such as nanowires. In this study, molecular dynamics simulations are employed to study the influence of H segregation on the behavior of intergranular cracks in bicrystalline α-Fe nanowires. The results demonstrate that segregated H atoms have weak embrittling effects on the predicted ductile cracks along the GBs, but favor the cleavage process of intergranular cracks in the theoretically brittle directions. Furthermore, it is revealed that cyclic loading can promote the H accumulation into the GB region ahead of the crack tip and overcome crack trapping, thus inducing a ductile-to-brittle transformation. This information will deepen our understanding on the experimentally-observed H-assisted brittle cleavage failure and have implications for designing new nanocrystalline materials with high resistance to HE.

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Mechanosynthesis of nanocrystalline materials

Hyperfine Interactions ◽

10.1007/bf02069130 ◽

1994 ◽

Vol 90 (1) ◽

pp. 229-242 ◽

Cited By ~ 12

Author(s):

G. Le Caër ◽

P. Matteazzi

Keyword(s):

Nanocrystalline Materials

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Application of Nanocrystalline Magnetic Materials in Electromechanical Devices

Materials Science Forum ◽

10.4028/www.scientific.net/msf.694.341 ◽

2011 ◽

Vol 694 ◽

pp. 341-344

Author(s):

Li Jun Wang ◽

Jie Qiong Li ◽

Hong Jing Wang

Keyword(s):

Magnetic Materials ◽

Nanocrystalline Materials ◽

Magnetic Loss ◽

Electronic Devices ◽

Silicon Steel ◽

Surveillance Systems ◽

Flux Reversal ◽

Telecommunication Equipment ◽

Electromechanical Devices ◽

Property Modification

Application of nanocrystalline magnetic materials in electromechanical devices is increasingly being adopted, helping to solve energy-saving problems and global warming. Compared with conventional silicon steel materials, nanocrystalline materials show faster flux reversal, lower magnetic loss and more versatile property modification, which result in the successful application in modern electronic devices. Nanocrystalline magnetic materials will be increasingly popularized and used in power electronics, telecommunication equipment and electronic article surveillance systems due to the demands for smaller and efficient devices in the future.

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