Enhanced adhesion of hard DLC coatings on metallic and insulating substrates

Diamond-Like Carbon (DLC) coatings have been recognized as one of the most valuable engineering materials for various industrial applications including manufacturing, transportation, biomedical and microelectronics. Among its properties, DLC has good frictional behaviour combined with high surface hardness, offering an elevated protection against abrasive wear.  

As the industrial success of DLC films in tribological contacts is strongly dependent on their adhesion properties, two different approaches were used to enhance DLC coating adhesion onto both metallic and insulating substrates.

-          HiPIMS metal ion etching and implantation with both Ti and Cr plasmas was used to pre-treat the M2-HSS metallic substrates, obtaining Rockwell HF1 values and critical loads in the macro-scratch tests above 100N .

-          Positive ion-assisted pre-treatment [1] was used to etch glass substrates and promote strong adhesion of thin DLC layers. Taber abrasion tests were performed to evaluate the pre-treatment process effect on the coating adhesion. A significant DLC coating adhesion improvement was observed.