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Validation of Proposed Metrics for Two-Body Abrasion Scratch Test Analysis Standards
Publications
  • Ryan L. Kobrick, University of Colorado Boulder
  • David M. Klaus, University of Colorado Boulder
  • Kenneth W. Street, NASA Glenn Research Center
Submitting Campus
Daytona Beach
Department
Applied Aviation Sciences
Document Type
Report
Publication/Presentation Date
2-1-2011
Abstract/Description

The objective of this work was to evaluate a set of standardized metrics proposed for characterizing a surface that has been scratched from a two-body abrasion test. This is achieved by defining a new abrasion region termed “Zone of Interaction” (ZOI). The ZOI describes the full surface profile of all peaks and valleys, rather than just measuring a scratch width as currently defined by the ASTM G 171 Standard. The ZOI has been found to be at least twice the size of a standard width measurement, in some cases considerably greater, indicating that at least half of the disturbed surface area would be neglected without this insight. The ZOI is used to calculate a more robust data set of volume measurements that can be used to computationally reconstruct a resultant profile for detailed analysis. Documenting additional changes to various surface roughness parameters also allows key material attributes of importance to ultimate design applications to be quantified, such as depth of penetration and final abraded surface roughness. Data are presented to show that different combinations of scratch tips and abraded materials can actually yield the same scratch width, but result in different volume displacement or removal measurements and therefore, the ZOI method is more discriminating than the ASTM method scratch width. Furthermore, by investigating the use of custom scratch tips for our specific needs, the usefulness of having an abrasion metric that can measure the displaced volume in this standardized manner, and not just by scratch width alone, is reinforced. This benefit is made apparent when a tip creates an intricate contour having multiple peaks and valleys within a single scratch. This work lays the foundation for updating scratch measurement standards to improve modeling and characterization of three-body abrasion test results.

Location
Cleveland, OH
Paper Number
NASA/TM—2011-216940
Number of Pages
14
Additional Information

Dr. Kobrick was not affiliated with Embry-Riddle Aeronautical University at the time this paper was published.

Citation Information
Ryan L. Kobrick, David M. Klaus and Kenneth W. Street. Validation of Proposed Metrics for Two-Body Abrasion Scratch Test Analysis Standards. (2011)
Available at: http://works.bepress.com/ryinspace/34/