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dc.contributor.authorValentino, Jeffrey Josephen
dc.date.accessioned2014-03-14T21:32:46Zen
dc.date.available2014-03-14T21:32:46Zen
dc.date.issued1997-08-19en
dc.identifier.otheretd-04042000-23160045en
dc.identifier.urihttp://hdl.handle.net/10919/41888en
dc.description.abstractAdvanced ceramic materials have found many new applications in the automotive and other industries. To satisfy demands of higher temperatures and inert surfaces, new lubrication methods for these ceramics need explored and evaluated. This thesis focuses on a boundary lubrication method termed tribopolymerization -- the formation of polymers at the tribological interphase. The research evaluated new high-temperature classes of anti-wear additives. The work involved experiments on steel and alumina material pairs with a pin-on-disk tribometer used to explore the anti-wear capabilities of selected additives in the liquid phase at concentrations of 1% by weight in hexadecane.

New additives included aromatic compounds with various pendant groups adding the design functionality necessary for in-situ polymerization. The amino, hydroxyl, acid, and ester functional groups underwent studies across several aromatic molecular compositions while new heterocyclic additives, in particular the readily available lactams, underwent exploratory tests as a new class under the tribopolymerization design approach. In concentrations of 1%, additives showed significant wear reductions of up to 99.9 %. Anti-wear behavior persisted in select cases at concentrations as low as 0.1% by weight. Compounds from two new classes demonstrated anti-wear behavior at 6x the frictional heat generation of standard exploratory conditions. This surprising effect partially filled a void in the effective range of operating conditions between 0.25 m/s, 40 N and 1.0 m/s, 160 N. Earlier work by Tritt found a complete absence of anti-wear behavior for the previous additive classes at the high-speed conditions.

In addition, several individual compounds constituent to an A-R-A + B-R'-B condensation polymerization reaction demonstrated significant anti-wear behavior when used alone. In particular, the compound BTDA from DuPont's Kapton ® exhibited higher wear reductions than any other new additive.

These findings support tribopolymerization as an effective approach to boundary lubricant design. Low wear was often associated with an attached reaction debris layer. This finding is consistent with previous work involving tribopolymerization anti-wear additives with ceramics. Further research into the roles of the debris layer and tribochemistry will help in understanding the complex anti-wear behavior of these new high-temperature additive classes.

en
dc.publisherVirginia Techen
dc.relation.haspart1_JJV_Thesis_1_of_3.pdfen
dc.relation.haspart2_JJV_Thesis_2_of_3.pdfen
dc.relation.haspart3_JJV_Thesis_3_of_3.pdfen
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectanti-wearen
dc.subjectaluminaen
dc.subjecttribologyen
dc.subjecttribopolymerizationen
dc.subjectlubricationen
dc.subjectceramicsen
dc.titleTribopolymerization: Anti-Wear Behavior of New High Temperature Additive Classesen
dc.typeThesisen
dc.contributor.departmentMechanical Engineeringen
dc.description.degreeMaster of Scienceen
thesis.degree.nameMaster of Scienceen
thesis.degree.levelmastersen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.disciplineMechanical Engineeringen
dc.contributor.committeechairFurey, Michael J.en
dc.contributor.committeememberVick, Brian L.en
dc.contributor.committeememberEiss, Norman S. Jr.en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-04042000-23160045/en
dc.date.sdate2000-04-04en
dc.date.rdate2002-11-06en
dc.date.adate2001-11-06en


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