Superhard C-DLC coatings deposited by means of HIPIMS/UBM sputtering

Superhard, wear-resistant, low-friction C-DLC coatings may be deposited by sputtering pure graphite in a weak-reactive Ar +C2H2atmosphere. A dedicated design of the sputtering apparatus is essential Basic precondition is the uniform distribution of the plasma inside the chamber. This is achieved by operating the plasmagenerating unbalanced magnetrons (UBM) with a central anode allowing a gentle bombardment (75 eV) of the growing films by Ar and reactive gas ions. Sufficient adhesion is provided utilizing a WC interface architecture prepared by HIP IMS and UBM sputtering. Excellent film properties characterise two types of coatings with differing hydrogen content: CH 10 at.- [%]:HU > 50 GPat wear