Abstract
The tetrahedral amorphous carbon (ta-C) coating is one of the fascinating surface coating for superior mechanical properties. Although its outstanding mechanical strength, it is hard to achieve adhesion stability due to high interfacial and residual stresses. Here, we introduce a new concept of pretreatment called large pulsed electron beam (LPEB) treatment. To specify the adhesion of the ta-C coating following the LPEB treatment, various adhesion tests, including the scratch test and Rockwell indentation test, were conducted. Thus, the ta-C coating pretreated with LPEB was found to have excellent adhesion through qualitative and quantitative analyses. Furthermore, to elucidate the mechanism for improving adhesion, analyses were conducted from two aspects: 1) deformation of the substrate and 2) stress change at the interface between the coating and the substrate. As a result, ta-C pretreated with LPEB increased the hardness of the substrate and supported the coating well. In addition, the thermal contraction of the coating was decreased after deposition, reducing the stress between the coating and the interface, and the adhesion was considerably improved.
NSTL
Elsevier