Investigation of Nanomechanical and Aging Properties of Scratch-Resistant Coatings on Polycarbonate through Nanoindentation

Abstract

Polycarbonate has been widely used in optical and aeronautic areas due to its low weight, transparency and high impact strength. The deposition of hard, transparent and scratch-resistant coatings on polycarbonate can significantly improve the surface mechanical behavior while capitalizing on their desirable bulk characteristics. In this work, nanomechanical properties of transparent scratch-resistant coating on polycarbonate, including nanoindentation and nanoscratch behaviors, were detailed investigated. The significant enhancement of nanomechanical response, containing hardness elastic modulus and friction-resistance, could be obtained after the deposition of the scratch-resistant coating. The results of the systematic investigation of indentation and scratch performance at the nanoscale reveal their significant differences between the surface region and bulk of coatings. Furthermore, the aging properties of scratch-resistant coatings under hygrothermal environment (65°C water for different time) can be followed-up and quantitatively detected in terms of hardness and maximum loading depth changing by nanoindentation technique, which prove to be a new and available method to study aging behavior of thin coatings.