Si3N4–TiN based micro-laminates with rising R-curve behaviour

Two different Si3N4–TiN based micro-laminates were successfully designed and manufactured (by tape casting) with a rising R-curve behaviour. These laminates were successfully designed to have maximum apparent fracture toughnesses of 10.5 and 18.0 MPa m1/2. Thin compressive Si3N4 layers of 50 μm thickness were used to control the residual stresses and hence the apparent fracture toughness in the micro-laminates. No ‘edge cracking’, crack deflection or crack bifurcation was observed in the two designs of micro-laminates studied.