scope:

This part of ISO 14577 specifies a method for testing coatingswhich is particularly suitable for testing in the nano/micro rangeapplicable to thin coatings. However, the application of thismethod of this part of ISO 14577 is not needed if the indentationdepth is such a small fraction of the coating thickness that in anypossible case a substrate influence can be neglected and thecoating can be considered as a bulk material. Limits for such casesare given. This test method is limited to the examination of singlelayers when the indentation is carried out normal to the test piecesurface, but graded and multilayer coatings can also be measured incross-section if the thickness of the individual layers orgradations is greater than the spatial resolution of theindentation process. The test method is not limited to anyparticular type of material. Metallic and non-metallic coatings areincluded in the scope of this part of ISO 14577. In this part ofISO 14577, the term coating is used to refer to any solid layerwith homogeneous properties different to that of a substrate it isconnected to. The method assumes that coating properties areconstant with indentation depth. Composite coatings are consideredto be homogenous if the structure size is less than the indentationsize. The application of this part of ISO 14577 regardingmeasurement of indentation hardness is only possible if theindenter is a pyramid or a cone with a radius of tip curvaturesmall enough for plastic deformation to occur within the coating.The hardness of visco-elastic materials or materials exhibitingsignificant creep will be strongly affected by the time taken toperform the test.