Sintering temperature effect on microstructure, mechanical and electrical properties of multi-layered ZrB2-based ceramics with thin Ti interlayer

Laminated ZrB2-SiCW ceramics with a thin Ti interlayer were synthesized via spark plasma sintering at varying temperatures. The effect of sintering temperature on the interlayer morphology, phase composition, and mechanical properties of laminated ZrB2-SiCW/Ti ceramics was assessed. With increasing sintering temperature from 1600 degrees C to 1800 degrees C, element diffusion between the matrix and the interlayer gradually increased. The green-body ductile Ti gradually transformed into a multiphase mixture with increasing hardness at the interlayer, shortening the crack propagation path. The toughening mechanisms changed from delamination to deflection, leading to a decrease in fracture toughness from 15.30 +/- 0.72 +/- 11.21 +/- 0.45 MPa m(1/2). Compared to monolithic ZrB2-SiCW ceramics, the introduction of multiple toughening mechanisms significantly improved the toughness of laminated ceramics with a small loss in strength. The electrical conductivity under parallel and perpendicular directions decreased with the decrease in residual Ti, with an important effect on electromagnetic effectiveness, reduced from 61.5 to 45.1 dB.