ASTM D7187-20,Standard Test Method for Measuring Mechanistic Aspects of Scratch/Mar Behavior of Paint Coatings by Nanoscratching.
ASTM D7187-20 covers a nanoscratch method for determining the resistance of paint coatings on smooth flat surfaces to scratch/mar.
ASTM D7187-20 is particularly suitable for measurement of paint coatings on laboratory test panels.
3. Summary of Test Method
3. 1 This test method is based on representative samples of the paint film being scratched using a nanoscratch instrument.From information generated during a scratch test, values for plastic resistance (PR) and fracture resistance (FR) can be determined. From these values, the mechanistic aspects of scratch/mar behavior of the coating can be compared.
6. 1 The substrate for the paint coating should be a smooth,plane,rigid surface, such as those specified in Practices D60 and D823.
6.2 The thickness of the coating being tested, determined inaccordance with either Test Methods dinos or D709, should be uniform within 5 %o of coating thickness.
6.3 At least three scratches shall be performed on each test.