CHARACTERIZATION BY GLANCING ANGLE X-RAY-DIFFRACTION OF THE INTERFACE BETWEEN AUSTENITIC STAINLESS-STEEL AISI-304 SUBSTRATES AND A TIN OR TI/TIN PHYSICAL VAPOR-DEPOSITION COATING

Abstract

The interface between an austenitic stainless steel AISI 304 substrate surface and a TiN or Ti/TiN coating is studied by means of glancing angle X-ray diffraction. Depending on the deposition conditions, the presence of gamma'-Fe4N can be observed in the case where no titanium intermediate layer is deposited. The effect of the interface on the adhesion of the TiN coating is studied by means of the scratch test method. It is found that the formation of a gamma'-Fe4N layer has a deleterious effect on the adhesion and that much better adhesion is obtained when the formation of such a layer is avoided, even without the presence of a titanium intermediate layer. These results are correlated with adhesion measurements of the coatings performed with the scratch test method.