Discontinuous cracking of TiN films on a steel substrate induced by an adhesive interlayer

Abstract

The basic mechanisms governing the process of cracking of single-layer brittle films have been extensively explored through both simulations and experiments.However, the role that an adhesive interlayer plays in the cracking of the overlying brittle film remains unclear. By performing three-point bending experiments, we observed that the insertion of a 100 nm thick Ti interlayer changed the cracking behavior of TiN films from a continuous pattern to a discontinuous pattern. The slight change in the microstructure of the film and the increase in film thickness arising from the addition of the Ti interlayer are unlikely to cause the observed cracking morphology.

Glass-Ceramic Protective Coatings Based on Metallurgical Slag

“…Thus, it is possible to assume that the phases supporting adhesion, in particular α-Fe 2 O 3 and ferrites (NiFe 2 O 4 ), formed during a firing as a result of the redox processes [31]. The data of the EDS point analysis (Figure 4, Table 4) indicate that interdiffusion occurs at the interface during the firing of green coatings [26]. The interlayer is formed as a result of the metal substrate oxidation and diffusion of the glass components into the Fe 2 O 3 structure.…”

“…That is why, the batch, which allows producing the glass composition No 5 characterized with CTE theor . < CTE steel but closer to CTE steel (Table 3), was chosen for the following experiments, taking into account traditional requirements of the enameling [25,26]. Some preliminary experiments were conducted on the fusion and crystallization of the glass compositions based on the batches No 1-5 and confirmed the correctness of the choice of the batch No 5 as the optimal composition in terms of the thermal expansion properties (experimental CTE values).…”