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Tribology and Corrosion in CoCrMo Alloys and Similar Systems.

Record Type:	Language materials, manuscript : Monograph/item
Title/Author:	Tribology and Corrosion in CoCrMo Alloys and Similar Systems./
Author:	Hoffman, Emily E.
Description:	1 online resource (245 pages)
Notes:	Source: Dissertation Abstracts International, Volume: 78-08(E), Section: B.
Contained By:	Dissertation Abstracts International78-08B(E).
Subject:	Materials science. -
Online resource:	click for full text (PQDT)
ISBN:	9781369678956

Tribology and Corrosion in CoCrMo Alloys and Similar Systems.
Hoffman, Emily E.

Tribology and Corrosion in CoCrMo Alloys and Similar Systems. - 1 online resource (245 pages)

Source: Dissertation Abstracts International, Volume: 78-08(E), Section: B.

Thesis (Ph.D.)

Includes bibliographical references

The artificial hip is a rich environment for the tribologist. This research investigated tribology and corrosion in CoCrMo alloy hip implants and extended the characterization methods and analyses to similar systems. The first project examined differences in corrosion behavior in the biomedical CoCrMo alloy using TEM and EDS. At the corroding grain boundaries, we found nanoscale chromium-rich carbides. These carbides caused chromium depleted zones which leads to corrosion, a process commonly referred to as sensitization. The chromium depletion and grain boundary crystallography data were used to develop a model showing nanoscale sensitization initiated grain boundary crevice corrosion. The next area of research looked at nanotribology of solid lubricants and formation of tribolayers. In situ TEM was used to directly observe the sliding interface of nanoflakes of molybdenum disulfide. Investigating low friction mechanisms of the lamellar solid lubricant revealed that the deck-of-cards sliding assumption present in the literature was not true. Instead, we showed sliding and transfer layer formation occurred at one interface only. The in situ sliding tests also revealed that the nanoflakes are unstable during sliding due to rolling, reorientation, flake pull apart, and adhesion changes. The final project analyzed a variety of carbon tribofilms, including the tribolayer found in metal-on-metal hips and the varnish tribofilm that forms in industrial machines. We characterized the carbon varnish film and showed similarities to published work on other graphitic carbon films. By comparing the nanoscale bonding and formation mechanisms, striking similarities were found that could inspire future cross-discipline advancements. Together, this work examined the relationships between wear, corrosion, and tribology to connect nanoscale structure and composition to applied performance.

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

Mode of access: World Wide Web

ISBN: 9781369678956Subjects--Topical Terms:

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

554714
Electronic books.

Tribology and Corrosion in CoCrMo Alloys and Similar Systems.
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500 $a Source: Dissertation Abstracts International, Volume: 78-08(E), Section: B.
500 $a Includes supplementary digital materials.
500 $a Adviser: Laurence D. Marks.
502 $a Thesis (Ph.D.) $c Northwestern University $d 2017.
504 $a Includes bibliographical references
520 $a The artificial hip is a rich environment for the tribologist. This research investigated tribology and corrosion in CoCrMo alloy hip implants and extended the characterization methods and analyses to similar systems. The first project examined differences in corrosion behavior in the biomedical CoCrMo alloy using TEM and EDS. At the corroding grain boundaries, we found nanoscale chromium-rich carbides. These carbides caused chromium depleted zones which leads to corrosion, a process commonly referred to as sensitization. The chromium depletion and grain boundary crystallography data were used to develop a model showing nanoscale sensitization initiated grain boundary crevice corrosion. The next area of research looked at nanotribology of solid lubricants and formation of tribolayers. In situ TEM was used to directly observe the sliding interface of nanoflakes of molybdenum disulfide. Investigating low friction mechanisms of the lamellar solid lubricant revealed that the deck-of-cards sliding assumption present in the literature was not true. Instead, we showed sliding and transfer layer formation occurred at one interface only. The in situ sliding tests also revealed that the nanoflakes are unstable during sliding due to rolling, reorientation, flake pull apart, and adhesion changes. The final project analyzed a variety of carbon tribofilms, including the tribolayer found in metal-on-metal hips and the varnish tribofilm that forms in industrial machines. We characterized the carbon varnish film and showed similarities to published work on other graphitic carbon films. By comparing the nanoscale bonding and formation mechanisms, striking similarities were found that could inspire future cross-discipline advancements. Together, this work examined the relationships between wear, corrosion, and tribology to connect nanoscale structure and composition to applied performance.
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 Northwestern University. $b Materials Science and Engineering. $3 1181794
773 0 $t Dissertation Abstracts International $g 78-08B(E).
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