ZrB2-Based Laminates Produced by Tape Casting

ZrB2-based laminates were produced by tape-casting and pressureless sintered at 2150°C in argon atmosphere using silicon nitride as sintering aids. Two different configurations were considered: planar (tile) and tubular (roll). After sintering, the laminates reached different relative densities depending on their composition (with or without SiC additions as secondary phase) or the final shape (tiles or rolls). Traces of the formation of oxygen-free crystalline phases such as B4C and BN were found in all samples. The RT flexural strength of bars cut from the tile configuration was mainly affected by the coarse microstructure, residual porosity and layers stacking sequence. A very low scattering of the flexural strength values was registered in ZrB2-SiC laminates because of the homogeneous microstructure and the absence of any defects between the layers. Tape casting allowed the production of thin homogenous laminates with a significant reduction of weight and a careful microstructure control