Wd. Shen et al., USE OF A SCANNING PROBE MICROSCOPE TO MEASURE MARRING MECHANISMS AND MICROHARDNESS OF CROSS-LINKED COATINGS, JCT, Journal of coatings technology, 69(873), 1997, pp. 125-137
Citations number
34
Categorie Soggetti
Chemistry Applied","Materials Science, Coatings & Films
A scanning probe microscope (SPM) was equipped with a high-modulus pro
be to indent coating surfaces when normal force is applied. A method f
or measuring microhardness with this probe is described. The high-modu
lus probe was also used to mar coating surfaces under controlled condi
tions by application of normal force plus lateral motion. Dimensions o
f the mars were measured by conventional scanning probe microscopy. Th
e data were analyzed in terms of a ''three response, two mechanism mod
el'' of marring in which three types of responses of polymeric materia
ls: elastic, plastic deformation, and fracture, are measured. Of the t
hree responses, only plastic deformation and fracture result in marrin
g, and the two mechanisms can be quantified. A fourth quantity which c
ombines plastic deformation and fracture is suggested as a method of c
omparing ''micro mar resistance'' of materials under specified conditi
ons. Three crosslinked polymeric coatings were studied in detail. Two
had hard crusts of material near their surfaces that responded quite d
ifferently than the bulk of the material.