This work is mainly focused upon the analytical examination of the physical and
mechanical response of plastics undergoing an induced scratch deformation caused by a
semi-spherical scratch tip under a linearly increasing normal load. Evaluation of the
scratch deformations in this study was based upon visual and optical observations and
upon observations of failure and fracture mechanisms as well as Electron Microscopy
examinations. In the first section of this study an effort was made to correlate the scratch
resistance observed in Polypropylene (PP) thin sheets with material properties, such as
molecular weight and surface crystallinity. In the second section of this work the scratch
behavior of epoxy nanocomposites was examined and a conclusion was made based
upon the effects of the addition of nano-additives with various natures into the epoxy
matrix. Furthermore, a region of the scratch path prior to the onset of scratch visibility
known as the mar region, which was an obscure area of deformation on a microscopic
scale, was thoroughly investigated for the epoxy systems and various conclusions were
made based upon those results.
Finally, based on these findings and previous studies, it was shown that failure and fracture mechanisms of polymeric materials under scratch deformations are
dependent on the type and physical nature of the material, whereas brittle and ductile
materials show various behaviors under the specified conditions. Based on the failure
mechanism which the material exhibits subsequent to the scratch deformation process
and the physical and mechanical characteristics of the material, several factors were
shown to effect the materials ability to scratch resistance.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/ETD-TAMU-1941 |
| Date | 02 June 2009 |
| Creators | Moghbelli, Ehsan |
| Contributors | Su, Hung-Jue |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Book, Thesis, Electronic Thesis, text |
| Format | electronic, application/pdf, born digital |
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