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

Laminated ZrB₂-SiC_w 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-SiC_w/Ti ceramics was assessed. With increasing sintering temperature from 1600 ℃ to 1800 ℃, 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 to 11.21 ± 0.45 MPa m^1/2. Compared to monolithic ZrB₂-SiC_w 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.