Fig. 2
Effect of moisture-dependent interfacial bond strength on fatigue toughening. Fatigue fracture energy ΓFatigue of polymer-metal-ceramic structures with Cu-MPTMS-SiO2 interfaces shown for water partial pressures a \(p_{{\mathrm{H}}_{2}{\mathrm{O}}}\) = 1.9 kPa and b \(p_{{\mathrm{H}}_{2}{\mathrm{O}}}\) = 2.8 kPa. c ΓFatigue peak value, i.e., ΓFatigue-peak (red squares) and average ΓStatic (blue circles) plotted versus \(p_{{\mathrm{H}}_{2}{\mathrm{O}}}\) for stacks with Cu-MPTMS-SiO2 interfaces. Average ΓFatigue (green triangles) and ΓStatic (black stars) for stacks without MPTMS are also shown. There is no observable ΓFatigue peak for \(p_{{\mathrm{H}}_{2}{\mathrm{O}}}\) > 2.2 kPa (open red squares). d Leading edge frequency νLeading of the ΓFatigue peak for Cu-MPTMS-SiO2 interfaces. No ΓFatigue peak is observed for \(p_{{\mathrm{H}}_{2}{\mathrm{O}}}\) ≥ 2.2 kPa. Each data point represents at least three tests. The width of the bands, drawn through the data points to guide the eye, connote the experimental uncertainty measured as standard deviation
