On the relation between damage rate and stress level evolution in α-Cr2O3 thin films growing on Ni–33at%Cr

Limitations and Advantages of Raman Spectroscopy for the Determination of Oxidation Stresses

“…Similar to the data summarized in Table 2, these variations are not correlated to the type of Cr 2 O 3 standard used. For example, Mougin et al [6] and this work used spalled oxide pieces formed by the oxidation of Cr; Siab et al [27] used scraped oxides formed on Ni-30Cr; Kitamura et al [7] and also this work used pressed Cr 2 O 3 pellets from commercially available high purity Cr 2 O 3 powders. At higher temperatures, 750°C, the scattering is even greater at 8.9 cm -1 .…”

“…Several temperature dependencies of the Cr 2 O 3 A 1g band had been reported in the literature [6,7,27]. Figure 3 summarizes these results along with new measurements performed in this work on two types of Cr 2 O 3 standards: one is a sintered then fully annealed Cr 2 O 3 piece; another is a piece of oxide formed on high purity Cr that had spalled during cooling after oxidation at 900°C for 2 h. On the sintered piece, data were gathered from heating and cooling curves.…”

Estimation of the stress relief induced in CrN thin films by buckling

“…On the contrary, Cr 2 O 3 films have well defined Raman spectra with known temperature and pressure dependence laws [19,20] but cannot be used in this mechanical study due to its brittleness leading to immediate and complete spalling. To overcome this contradiction, the usual oxygen contamination layer present in the outermost layer of CrN thin films has been used to obtain a weak but well defined Raman spectrum [18,21].…”

Determination of Residual Stress Fields in a Thermally Grown Oxide under Thermal Cycling Loadings, Using XRD and Raman Spectroscopy — Correlations with Microstructural States

“…The normalised delamination rates are obtained from Eq. 1 [8] : S surface of buckle number j, S total surface, N and N' respectively total number of buckles and spalls. The later are observed thanks to optical microscopy and the quantitative measurements are performed through image analysis.…”

“…The determination of such growth or residual stress has already been undertaken [1][2][3][4][5][6][7]. And subsequent stress release may induce buckling or spalling phenomena which will renew oxidation of the metallic alloy [8][9][10]. In addition, stress release may also proceed by creep which should be less detrimental for the system.…”