MAGNETRON SPUTTERED Ti-BASIS HARD MATERIAL COATINGS ON THERMOPLASTIC POLYMERS FOR APPLICATIONS IN PARTICLE SENSITIVE ENVIRONMENTS

摘要

Even under demanding environments, like clean rooms, polymers are already used in different ranges of applications. The wear and particle generation within a specific particle size even under mechanical stress is a limiting factor. So it was the aim to develop an innovative material concept, that enables to apply a thermoplastic polymer coated with a thin hard material (thickness up to 2.5 μm), which also prevents for electrostatical discharges and is usable for complex bodies. Therefore it was necessary to improve the wear resistance and the adherence between the polymer and the coating. To take also economic aspects into consideration a two step production process sequence was required, consisting of the injection moulding process and then the plasma deposition process including a plasma pre-treatment. In this investigation, poly(butylene-terephthalate) (PBT) and poly(amide) 6.6 (PA) and polycarbonate (PC) were chosen as substrate material. The coating materials used, which were mainly deposited by Magnetron Sputter Ion Plating (MSIP), were on titanium basis (Ti-N). To get detailed chemical information about the coatings and the interfacial region they were analyzed by X-Ray Photoelectron Spectroscopy (XPS), additionally Secondary Ion Mass Spectrometry (SIMS) experiments were carried out to confirm the results. The process parameter's influence on the microstructure, which extend from amorphous to columnar (crystalline), and the film thickness were analyzed by SEM. It will be shown and discussed, that it is possible to improve the coating's adherence by plasmapre-treatment as well as to reduce the particle generation after a suitable etching and coating process.