Fig. 6

Simulation results obtained using cohesive finite element model (CFEM) for LuPO₄ and Lu₂SiO₅ microstructures at different levels of CMAS penetration. The fracture patterns in (a) LuPO₄ and (b) Lu₂SiO₅ EBC microstructures are shown with 0% CMAS (pure), 3% CMAS, 8% CMAS and 15% CMAS penetration. Panels (c,d) show average crack path fractions before and after CMAS penetration in LuPO₄ and Lu₂SiO₅, respectively. The J-integral values for (e) LuPO₄ and (f) Lu₂SiO₅ before and after CMAS penetration are compared with that of the pure CMAS with evolving crack length. Panels (g,h) compare fracture toughness (K_Ic) and residual strength before and after CMAS penetration in LuPO₄ and Lu₂SiO₅, respectively.