Evaluation of mechanical properties of carbon coatings synthesised in radio frequency plasma on PDMS

The paper presents the results of testing the mechanical properties of carbon coatings synthesised on a PDMS substrate by radio frequency plasma with various RF power. The synthesised coatings were characterised in terms of thickness measured by the profilometer and chemical structure determined using Raman spectroscopy. The modified PDMS substrates were tested with the use of the nanoindentation technique to specify changes in the modulus of elasticity and elastic recovery as a function of applied load. Additionally, the influence of modification on the adhesion and tribological properties of carbon coatings was determined. Specific insight into the fracture mechanism was achieved by expansion of the atomic force microscope (AFM) by additional stretching equipment. In this study, the fracture mechanism was observed step by step, as a function of the sample extension. The results of the tension tests of the PDMS substrates are evidence of the close correlation of the wear mechanisms of coatings with their fundamental properties, especially: chemical structure, elastic modulus and adhesion.