A rapid, non-destructive test to detect camshaft lobe grinding burn

The work presented herein describes thesis research in an on-going camshaft grinding evaluation study, initially under the sole sponsorship of Ford Motor Company, and subsequently under the auspices of the National Science Foundation, with industrial participation from American Stress Technologies, Ford Motor Company, G.E. Superabrasives and Litton Automotive Services. Six mechanically assembled camshafts were ground with each of their eight induction hardened lobes receiving a different depth of cut per pass. X-ray residual stress measurements made with depth identified significant near-surface tensile residual stresses in abusively ground regions of the lobes. Acid etching at the time of grinding and subsequent microhardness measurements were employed to verify the x-ray depth results. The grinding operation was further characterized with use of profile and roughness measurements. Burn (defined as a localized tempering of the cam lobe as a result of the grinding operation) appeared in those lobes that received the larger depth of cut, and was concentrated along the ramps and base circle. Several non-destructive examination techniques were then compared with each other to discover which best detected burn. Intercomparison involved evaluating the strength and consistency of the measurement signal. Background noise occurred in all cases due to the measurement technique, instrument error, and human error. Measurement of grinding forces and x-ray diffraction line width analysis were found to be suitable for rapidly and reliably detecting grinding burn in the induction-hardened carbon steel cam lobes. In this regard, it may now be possible to have reliable, quantitative, and non-destructive cam lobe examination in place of the traditional acid etching.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Materials Science and Engineering

Department dc:contributor.department

Materials Science and Engineering

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

1993

Author dc:creator

• Courtney, Scott B.

Chair dc:contributor.committeechair

• Hendricks, Robert Wayne

Committee members dc:contributor.committeemember

• Landgraf, Ronald W.
• Reynolds, William T. Jr.
• Whalen, Thomas J.

Statement dc:rights

• In Copyright

Licence dc:rights.uri

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

Language dc:language.iso

en

Dc Identifier Other

etd-09042008-063602

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/34921