Toughness and R-curve behaviour of laminated Si3N4/SiCw ceramics

Optical Performance, Thermal Stability, and Failure Analysis of the WNx-Si3N4 Multilayer Solar Selective Absorbing Coatings

“…Based on the above analysis, we believe that the failure of the SSAC deposited on the SS substrate at 700 °C might be mainly induced by the interdiffusion (not oxygen diffusion) between the films constructing the SSAC. The interdiffusion between the single layers is a kind of common failure mechanism of the SSACs. ,− Moreover, considering the impact of substrate materials on the thermal stability of WN x -Si 3 N 4 SSACs, we make a further hypothesis for the failure mechanism, as shown in Figure .…”

“…The detailed stress analysis and the roughly estimated stress values can be found in the Supporting Information. The WN x -Si 3 N 4 SSAC deposited on the SS substrate stretches and cracks at 700 °C because of the overlarge tensile stress and the big bulk of SS (3 × 3 × 0.1 cm) compared to the all-layer coating (3 cm × 3 cm × 0.5 μm). ,, The cracks provide the channels for the rapid diffusion of atoms. Also, the extent of cracking increases with the increasing thermal mismatch from the bottom TiN layer to the top SiO 2 layer.…”

Research and application of biomimetic modified ceramics and ceramic composites: A review

“…With the increase of the thickness, the bending strength of the composite ceramics increases from 218 to 350 MPa, and the Young's modulus increases from 136 to 175 Gpa. Wei et al 33 . prepared Si 3 N 4 /SiC w layered composite ceramics by tape casting and hot pressing sintering with SiC whiskers as interlayer.…”

“…According to the mapping relationship between structure and property, the toughening mechanism of biomimetic toughening ceramics can be divided into two types according to their different toughening structures. (1) Plastic deformation, friction dissipation, crack deflection, delamination cracking, and other mechanisms of biomimetic layered ceramics 2,33,89–92,212 . (2) Fiber bridging, crack deflection, fiber pullout, and other mechanisms of biomimetic fiber reinforced ceramics 5,6,33,34,36,110,116,213 .…”

“…When the interface bonding strength is weak, the crack will cause delamination at the interface junction and propagate through deflection under the action of different phase layers, as shown in the Figure 18a 2,90,91 . When the interface bonding strength is strong, the residual stress caused by different thermal expansion of different phase layers causes the crack to deflect and propagate in the layered ceramics, as shown in the Figure 18b 33,89 …”