國立虎尾科技大學 |

Application of ASTAR(TM)/Precession Electron Diffraction Technique to Quantitatively Study Defects in Nanocrystalline Metallic Materials.

Record Type:	Language materials, manuscript : Monograph/item
Title/Author:	Application of ASTAR(TM)/Precession Electron Diffraction Technique to Quantitatively Study Defects in Nanocrystalline Metallic Materials./
Author:	Ghamarian, Iman.
Description:	1 online resource (219 pages)
Notes:	Source: Dissertation Abstracts International, Volume: 79-04(E), Section: B.
Subject:	Materials science. -
Online resource:	click for full text (PQDT)
ISBN:	9780355334319

Application of ASTAR(TM)/Precession Electron Diffraction Technique to Quantitatively Study Defects in Nanocrystalline Metallic Materials.
Ghamarian, Iman.

Application of ASTAR(TM)/Precession Electron Diffraction Technique to Quantitatively Study Defects in Nanocrystalline Metallic Materials. - 1 online resource (219 pages)

Source: Dissertation Abstracts International, Volume: 79-04(E), Section: B.

Thesis (Ph.D.)--Iowa State University, 2017.

Includes bibliographical references

Nanocrystalline metallic materials have the potential to exhibit outstanding performance which leads to their usage in challenging applications such as coatings and biomedical implant devices. To optimize the performance of nanocrystalline metallic materials according to the desired applications, it is important to have a decent understanding of the structure, processing and properties of these materials.

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

Mode of access: World Wide Web

ISBN: 9780355334319Subjects--Topical Terms:

557839
Materials science.
Index Terms--Genre/Form:

554714
Electronic books.

Application of ASTAR(TM)/Precession Electron Diffraction Technique to Quantitatively Study Defects in Nanocrystalline Metallic Materials.
LDR:03989ntm a2200349K 4500 001 914081
005 20180703084420.5
006 m o u
007 cr mn||||a|a||
008 190606s2017 xx obm 000 0 eng d
020 $a 9780355334319
035 $a (MiAaPQ)AAI10257650
035 $a (MiAaPQ)iastate:16276
035 $a AAI10257650
040 $a MiAaPQ $b eng $c MiAaPQ
100 1 $a Ghamarian, Iman. $3 1187175
245 1 0 $a Application of ASTAR(TM)/Precession Electron Diffraction Technique to Quantitatively Study Defects in Nanocrystalline Metallic Materials.
264 0 $c 2017
300 $a 1 online resource (219 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: 79-04(E), Section: B.
500 $a Adviser: Peter C. Collins.
502 $a Thesis (Ph.D.)--Iowa State University, 2017.
504 $a Includes bibliographical references
520 $a Nanocrystalline metallic materials have the potential to exhibit outstanding performance which leads to their usage in challenging applications such as coatings and biomedical implant devices. To optimize the performance of nanocrystalline metallic materials according to the desired applications, it is important to have a decent understanding of the structure, processing and properties of these materials.
520 $a Various efforts have been made to correlate microstructure and properties of nanocrystalline metallic materials. Based on these research activities, it is noticed that microstructure and defects (e.g., dislocations and grain boundaries) play a key role in the behavior of these materials. Therefore, it is of great importance to establish methods to quantitatively study microstructures, defects and their interactions in nanocrystalline metallic materials.
520 $a Since the mechanisms controlling the properties of nanocrystalline metallic materials occur at a very small length scale, it is fairly difficult to study them. Unfortunately, most of the characterization techniques used to explore these materials do not have the high enough spatial resolution required for the characterization of these materials. For instance, by applying complex profile-fitting algorithms to X-ray diffraction patterns, it is possible to get an estimation of the average grain size and the average dislocation density within a relatively large area. However, these average values are not enough for developing meticulous phenomenological models which are able to correlate microstructure and properties of nanocrystalline metallic materials. As another example, electron backscatter diffraction technique also cannot be used widely in the characterization of these materials due to problems such as relative poor spatial resolution (which is ~90 nm) and the degradation of Kikuchi diffraction patterns in severely deformed nano-size grain metallic materials.
520 $a In this study, ASTAR(TM)/precession electron diffraction is introduced as a relatively new orientation microscopy technique to characterize defects (e.g., geometrically necessary dislocations and grain boundaries) in challenging nanocrystalline metallic materials. The capability of this characterization technique to quantitatively determine the dislocation density distributions of geometrically necessary dislocations in severely deformed metallic materials is assessed. Based on the developed method, it is possible to determine the distributions and accumulations of dislocations with respect to the nearest grain boundaries and triple junctions. Also, the competency of this technique to study the grain boundary character distributions of nanocrystalline metallic materials is presented.
533 $a Electronic reproduction. $b Ann Arbor, Mich. : $c ProQuest, $d 2018
538 $a Mode of access: World Wide Web
650 4 $a Materials science. $3 557839
655 7 $a Electronic books. $2 local $3 554714
690 $a 0794
710 2 $a ProQuest Information and Learning Co. $3 1178819
710 2 $a Iowa State University. $b Materials Science and Engineering. $3 1187176
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=10257650 $z click for full text (PQDT)