On Plowing Frictional Behavior during Scratch Testing: A Comparison between Experimental and Theoretical/Numerical Results

Scratch testing is a contact mechanics based nondestructive testing method that, if correctly evaluated, can give a lot of information about the material and tribological behavior of a material. In contrast to the situation with another contact-based method, indentation testing, wear characteristics can also be investigated, for example. In order to get results of practical importance from a scratch test, it is necessary to have evaluation formulae available. Indeed, such formulae exist for scratch testing but can be substantially influenced by frictional effects. For this reason, closed-form analytical relations have been suggested for the purpose of accounting for such effects during scratching and in particular the plowing frictional effect. As a major benefit, these relations can also be of assistance during material characterization through scratch testing. However, the proposed existing relations are based solely on theoretical/numerical analyses and, remembering that the scratch test of course is an experimental approach, verification by experiments is a necessity. Such a task is performed in the present study and it is shown that, based on standard contact global properties, the relations are accurate for most polymeric materials but could also be used for some metallic ones.