Corrosion behaviour of nanocomposite TiSiN coatings on steel substrates

Abstract

Nanocomposite TiSiN coatings were deposited on tool steels. Detailed mechanisms that govern the corrosion of these coated steels were revealed, following immersion tests in a 70% nitric acid solution. Pitting originated preferentially from coating defect sites and expanded with increasing immersion time. Both Young's modulus and hardness measured by nanoindentation decreased as the corrosion damage intensified. A thin oxide layer formed from the thermal annealing of the as-deposited samples at 900 C was found to be effective against corrosive attack. In addition, compressive residual stress was noted to suppress the 2 propagation of corrosion-induced cracks. The role of residual stress in controlling the corrosion resistance of these ceramic-coated steels is clarified by finite element analysis.

Comparison of crack resistance between ternary CrSiC and quaternary CrSiCN coatings via nanoindentation

“…3. Obviously, the main peak of all the CrSiCN coatings could be deconvoluted into two overlapped peaks related to Si-C bond around 101.1 eV and Si-N bond around 101.8 eV [24,[39][40][41]. Moreover, the volume fraction of Si-N bond increases with increasing Si concentration, and finally a novel and weak Si-Si bond presents at 99.2 eV due to higher Si incorporation in CrSiCN (30) …”

Corrosion‐ and Damage‐Resistant Nitride Coatings for Steel

“…(c) and (d)], Cr 2 O 3 was dominant on the CrN coating surface and can effectively seal corrosion pathways (i.e., structural defects) and thus imparting to the coating a greater corrosion resistance. According to the observation of structural defects in the coatings and XPS data, a model was proposed to elucidate the role of the oxide layer in amending surface defects and restoring the structural integrity (Fig. ).…”

“…18 For the uncoated steel sample, widespread intergranular corrosion was observed after electrochemical testing in both solutions [ Fig. 6(a) in the coatings 24 and XPS data, a model was proposed to elucidate the role of the oxide layer in amending surface defects and restoring the structural integrity (Fig. 7).…”

Structural evolution and electrochemical behaviors of multilayer Al-Cr-Si-N coatings

“…M.S. Ahmed et al [16] reported that the oxide layer formed from coatings surface and reduction of residual stress could increase the corrosion resistance of TiSiN coatings after 900 o C annealing. In addition, the nano-composite and multilayer structures, incorporation of the interlayer (such as PVD Al, Si etc.)…”