Scratch Test for Coating/Substrate Systems – A Literature Review

Abstract

The scratch test consists of a diamond stylus moving over the surface of a sample under a normal force which is increased either stepwise or continuously until a critical normal force is reached, at which point a well-defined coating failure occurs. This force is then taken as a measure of adhesion. In this paper, a literature review on scratch testing applied to coating/substrate systems is provided. Tribological contact mechanics, failure modes, factors affecting the scratch test results, adhesion measurements, friction effects as well as finite element modelling of the scratch test are discussed.

The scratch test consists of a diamond stylus moving over the surface of a sample under a normal force which is increased either stepwise or continuously until a critical normal force is reached, at which point a well-defined coating failure occurs. This force is then taken as a measure of adhesion. In this paper, a literature review on scratch testing applied to coating/substrate systems is provided. Tribological contact mechanics, failure modes, factors affecting the scratch test results, adhesion measurements, friction effects as well as finite element modelling of the scratch test are discussed.

L'essai de rayage consiste en un stylet en diamant se déplaçant à la surface d'un échantillon avec une force normale que l'on augmente soit par paliers ou continuellement jusqu'à ce qu'une force normale critique soit atteinte, au point auquel une défaillance bien définie du revêtement se produit. On prend ensuite cette force comme une mesure de l'adhésion. Dans ce document, on effectue une analyse documentaire de l'essai de rayage appliqué aux systèmes revêtement/substrat. On discute de la mécanique du contact tribologique, des modes de défaillance, des facteurs affectant les résultats de l'essai de rayage, des mesures d'adhésion, des effets de friction, ainsi que de la modélisation des éléments finis de l'essai de rayage.