Manually operated scratch tester for characterization of mechanical properties of thin films

Abstract

Based on the assumption that the results of a scratch test would not be affected significantly by some degree of variations of the rising rate of normal load and the speed of scratching, a manually operated scratch tester was developed for investigating the adhesion properties of coatings. The system can detect the friction force and normal load generated during a test, and identify the critical normal load L[sub c] where the friction force becomes unstable. Measurements were made on glass, zirconium nitride coatings and aluminum oxide coatings for examining the reliability of the system. L[sub c] of the three samples were 2.0±0.41 N, 1.4±0.32 N, and 0.52±0.13 N. Results show that the system is good enough to serve as an economical replacement for a conventional scratch tester.