國立虎尾科技大學 |

Deformation Behavior of Al/a-Si Core-shell Nanostructures.

Record Type:	Language materials, manuscript : Monograph/item
Title/Author:	Deformation Behavior of Al/a-Si Core-shell Nanostructures./
Author:	Fleming, Robert.
Description:	1 online resource (159 pages)
Notes:	Source: Dissertation Abstracts International, Volume: 79-01(E), Section: B.
Contained By:	Dissertation Abstracts International79-01B(E).
Subject:	Mechanical engineering. -
Online resource:	click for full text (PQDT)
ISBN:	9780355159585

Deformation Behavior of Al/a-Si Core-shell Nanostructures.
Fleming, Robert.

Deformation Behavior of Al/a-Si Core-shell Nanostructures. - 1 online resource (159 pages)

Source: Dissertation Abstracts International, Volume: 79-01(E), Section: B.

Thesis (Ph.D.)

Includes bibliographical references

Al/a-Si core-shell nanostructures (CSNs), consisting of a hemispherical Al core surrounded by a hard shell of a-Si, have been shown to display unusual mechanical behavior in response to compression loading. Most notably, these nanostructures exhibit substantial deformation recovery, even when loaded much beyond the elastic limit. Nanoindentation measurements revealed a unique mechanical response characterized by discontinuous signatures in the load-displacement data. In conjunction with the indentation signatures, nearly complete deformation recovery is observed. This behavior is attributed to dislocation nucleation and annihilation events enabled by the 3-dimensional confinement of the Al core. As the core confinement is reduced, either through an increase in confined core volume or a change in the geometrical confinement, the indentation signatures and deformation resistance are significantly reduced.

Electronic reproduction.
Ann Arbor, Mich. :
ProQuest,
2018

Mode of access: World Wide Web

ISBN: 9780355159585Subjects--Topical Terms:

557493
Mechanical engineering.
Index Terms--Genre/Form:

554714
Electronic books.

Deformation Behavior of Al/a-Si Core-shell Nanostructures.
LDR:03769ntm a2200397Ki 4500 001 908734
005 20180330125241.5
006 m o u
007 cr mn||||a|a||
008 190606s2017 xx obm 000 0 eng d
020 $a 9780355159585
035 $a (MiAaPQ)AAI10616915
035 $a (MiAaPQ)uark:12753
035 $a AAI10616915
040 $a MiAaPQ $b eng $c MiAaPQ
099 $a TUL $f hyy $c available through World Wide Web
100 1 $a Fleming, Robert. $3 1179001
245 1 0 $a Deformation Behavior of Al/a-Si Core-shell Nanostructures.
264 0 $c 2017
300 $a 1 online resource (159 pages)
336 $a text $b txt $2 rdacontent
337 $a computer $b c $2 rdamedia
338 $a online resource $b cr $2 rdacarrier
500 $a Source: Dissertation Abstracts International, Volume: 79-01(E), Section: B.
500 $a Adviser: Min Zou.
502 $a Thesis (Ph.D.) $c University of Arkansas $d 2017.
504 $a Includes bibliographical references
520 $a Al/a-Si core-shell nanostructures (CSNs), consisting of a hemispherical Al core surrounded by a hard shell of a-Si, have been shown to display unusual mechanical behavior in response to compression loading. Most notably, these nanostructures exhibit substantial deformation recovery, even when loaded much beyond the elastic limit. Nanoindentation measurements revealed a unique mechanical response characterized by discontinuous signatures in the load-displacement data. In conjunction with the indentation signatures, nearly complete deformation recovery is observed. This behavior is attributed to dislocation nucleation and annihilation events enabled by the 3-dimensional confinement of the Al core. As the core confinement is reduced, either through an increase in confined core volume or a change in the geometrical confinement, the indentation signatures and deformation resistance are significantly reduced.
520 $a Complimentary molecular dynamics simulations show that a substantial amount of dislocation egression occurs in the core of CSNs during unloading as dislocations annihilate at the core/shell interface. Smaller core diameters correlate with the development of a larger back-stress within the core during unloading, which further correlates with improved dislocation annihilation after unloading. Furthermore, dislocations nucleated in the core of core-shell nanorods are not as effectively removed as compared to CSNs.
520 $a Nanostructure-textured surfaces (NSTSs) composed of Al/a-Si CSNs have improved tribological properties compared surfaces patterned with Al nanodots and a flat (100) Si surface. NSTSs have a coefficient of friction (COF) as low as 0.015, exhibit low adhesion with adhesion forces on the order of less than 1 microN, and are highly deformation resistant, with no apparent surface deformation after nanoscratch testing, even at contact forces up to 8000 microN. In comparison, (100) Si has substantially higher adhesion and COF (~10 microN and ~0.062, respectively), while the Al nanodots have both higher friction (COF ~0.044) and are deformed when subjected to contact loads as low as 250 microN.
520 $a This integrated experimental and computational study elucidates the mechanisms that contribute to the novel properties of Al/a-Si CSNs and characterizes the tribological properties of surface composed of these nanostructures, which provides a foundation for the rational design of novel technologies based on CSNs.
533 $a Electronic reproduction. $b Ann Arbor, Mich. : $c ProQuest, $d 2018
538 $a Mode of access: World Wide Web
650 4 $a Mechanical engineering. $3 557493
650 4 $a Materials science. $3 557839
650 4 $a Nanoscience. $3 632473
655 7 $a Electronic books. $2 local $3 554714
690 $a 0548
690 $a 0794
690 $a 0565
710 2 $a ProQuest Information and Learning Co. $3 1178819
710 2 $a University of Arkansas. $b Mechanical Engineering. $3 1148579
773 0 $t Dissertation Abstracts International $g 79-01B(E).
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=10616915 $z click for full text (PQDT)