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Structural and Mechanical Characterization of Nanocrystalline Tungsten and Tungsten-Based Alloy Thin Films for Extreme Environment Applications.

Record Type:	Language materials, manuscript : Monograph/item
Title/Author:	Structural and Mechanical Characterization of Nanocrystalline Tungsten and Tungsten-Based Alloy Thin Films for Extreme Environment Applications./
Author:	Martinez, Gustavo.
Description:	1 online resource (172 pages)
Notes:	Source: Dissertation Abstracts International, Volume: 78-11(E), Section: B.
Contained By:	Dissertation Abstracts International78-11B(E).
Subject:	Mechanical engineering. -
Online resource:	click for full text (PQDT)
ISBN:	9780355053487

Structural and Mechanical Characterization of Nanocrystalline Tungsten and Tungsten-Based Alloy Thin Films for Extreme Environment Applications.
Martinez, Gustavo.

Structural and Mechanical Characterization of Nanocrystalline Tungsten and Tungsten-Based Alloy Thin Films for Extreme Environment Applications. - 1 online resource (172 pages)

Source: Dissertation Abstracts International, Volume: 78-11(E), Section: B.

Thesis (Ph.D.)

Includes bibliographical references

Extreme environments associated with nuclear applications often results in degradation of the physical, mechanical and thermo-mechanical properties of the materials. Tungsten (W) exhibits unique physical and mechanical properties, which makes tungsten a good candidate for nuclear applications; however, intrinsic W exhibits low fracture toughness at all temperatures in addition to a high ductile to brittle transition. In the present work, nanocrystalline W, W-Y and W-Mo alloys were nanoengineered for nuclear applications.

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

Mode of access: World Wide Web

ISBN: 9780355053487Subjects--Topical Terms:

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

554714
Electronic books.

Structural and Mechanical Characterization of Nanocrystalline Tungsten and Tungsten-Based Alloy Thin Films for Extreme Environment Applications.
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245 1 0 $a Structural and Mechanical Characterization of Nanocrystalline Tungsten and Tungsten-Based Alloy Thin Films for Extreme Environment Applications.
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300 $a 1 online resource (172 pages)
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500 $a Source: Dissertation Abstracts International, Volume: 78-11(E), Section: B.
500 $a Adviser: Ramana Chintalapalle.
502 $a Thesis (Ph.D.) $c The University of Texas at El Paso $d 2017.
504 $a Includes bibliographical references
520 $a Extreme environments associated with nuclear applications often results in degradation of the physical, mechanical and thermo-mechanical properties of the materials. Tungsten (W) exhibits unique physical and mechanical properties, which makes tungsten a good candidate for nuclear applications; however, intrinsic W exhibits low fracture toughness at all temperatures in addition to a high ductile to brittle transition. In the present work, nanocrystalline W, W-Y and W-Mo alloys were nanoengineered for nuclear applications.
520 $a Nanocrystalline tungsten coatings with a thickness of ~1 microm were deposited onto Silicon (100) and Sapphire (C-plane) using RF and DC sputtering techniques under various growth conditions. Yttrium content in W-Y alloys has been varied to enhance the irradiation tolerance under optimum concentration. The W, W-Y coatings were characterized to understand the structure and morphology and to establish a mapping of conditions to obtain phase and size controlled materials. The samples were then subjected to depth-controlled irradiation by neutrons and Au3+ ions. Solid solution strengthening was achieved by doping molybdenum (Mo) solute atoms to W matrix under varied sputtering pressures and temperatures with the intention of creating interstitial point defects in the crystals that impede dislocation motion, increasing the hardness and young modulus of the material. The effect of PAr (3-19 mTorr) was also investigated and associated microstructure are significant on the mechanical characteristics; the hardness (H) and modulus of elasticity (Er) of the nc W-Mo thin films were higher at lower pressures but decreases continuously with increasing PAr.
520 $a Using nano-indentation and nano-scratch technique, mechanical characterization testing was performed before and after irradiation. The structure, mechanics and irradiation stability of the W and W-Y coatings will be presented and discussed to demonstrate that Y-addition coupled with nano-scale features dramatically improve the irradiation tolerance of the coatings. The structure-phase-mechanical-electrical property correlation established suggests that further options may exist to tailor the quality and performance of W-Mo films for future electronic and electromechanical device applications.
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 Nanotechnology. $3 557660
655 7 $a Electronic books. $2 local $3 554714
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690 $a 0794
690 $a 0652
710 2 $a ProQuest Information and Learning Co. $3 1178819
710 2 $a The University of Texas at El Paso. $b Mechanical Engin.. $3 1178954
773 0 $t Dissertation Abstracts International $g 78-11B(E).
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=10598958 $z click for full text (PQDT)