The effect of molecular weight on the behavior of polystyrene coated steel disks under fretting conditions

Thin polymeric coatings have been applied to metal surfaces to prevent and/or prolong the onset of fretting corrosion, but the properties that make a polymeric coating effective and the means by which a coating fails are unknown. The purpose of this study was to determine the effect of molecular weight, casting solvent, and amplitude of motion on the life of thin (25 ~m nominal) polystyrene coatings. Narrow molecular weight distribution polystyrene coatings ranging from <Mw>=19,400 to <Mw>=1,460,000 were applied to UNS G10450 steel disks with toluene and MEK as casting solvents. The coatings were fretted against UNS G52100 steel balls at 20 Hz under 22.3 N normal load. Amplitudes of motion ranged from 100 ~m to 500 ~m. Coating life and friction force were measured. Coatings of <Mw>=207,700 showed maximum life at all amplitudes. Friction remained constant for all tests, and increasing amplitude decreased life. Toluene-cast coatings had slightly shorter lives and more coating racks than MEK-cast coatings. Toluene-cast coatings below <Mw>=53,700 cracked severely during solvent removal and were not tested.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Mechanical Engineering

Department dc:contributor.department

Mechanical Engineering

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

1988

Author dc:creator

• Bradley, Randall S.

Chair dc:contributor.committeechair

• Eiss, Norman S. Jr.

Committee members dc:contributor.committeemember

• Furey, Michael J.
• Taylor, Larry T.

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Dc Identifier Other

etd-07212010-020238

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/43837