Quantitative modeling of scratch behavior of amorphous polymers at elevated temperatures

The scratch resistance of polymeric materials is generally known to deteriorate with increasing temperature of testing. The present study focuses on quantitatively predicting the effect of temperature on the scratch behavior of amorphous polymers. The Arruda-Boyce viscoplastic model is utilized to account for temperature and strain rate dependent strain-softening and strain-hardening behaviors. The post-yield behavior predicted in this model is calibrated using the yield point determined by the Richeton cooperative model. The pressure dependent Drucker-Prager model with calibrated post-yield experimental data at various strain rates is chosen as the plastic constitutive relationship of the polymeric systems for FEM simulation. Furthermore, temperature and pressure dependent frictional behavior is input into an ABAQUS contact model to simulate the variation of the adhesion coefficient of friction (μ_a) during the ASTM standardized linearly increasing load scratch test. The FEM simulation findings show a good agreement with the experimentally determined scratch depth and scratch coefficient of friction (SCOF) measured using the scratch test. Usefulness of the present study for design of scratch resistant polymers at elevated temperatures is discussed.