Microstructure evolution upon annealing of a ZrB2–SiC composite containing lanthana and magnesia

Silvestroni, L.; Sciti, Diletta

doi:10.1016/j.jeurceramsoc.2012.08.034

Cited by 9 publications

(1 citation statement)

References 22 publications

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“…[26] Positive consequences have also been demonstrated on the elevated temperature mechanical properties of both SiC and Si 3 N 4 structural ceramics [27,28] and, more recently, on UHTCs. [29][30][31] Analysis by transmission electron microscopy (TEM)…”

Section: Introductionmentioning

confidence: 99%

A simple route to fabricate strong boride hierarchical composites for use at ultra-high temperature

Silvestroni

Gilli

Migliori

et al. 2020

Composites Part B: Engineering

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A simple method to obtain a highly refractory HfB 2 -based ceramic nano-composite is presented. The boride was hot pressed with additions of SiC and WC particles and subsequently annealed at 2100°C for 2 hours.The annealing procedure was beneficial for high temperature strength, which increased by about 300 MPa in the 1500°C to 1800°C temperature range compared to the as-sintered material. Peak strengths of 850 MPa at 1500°C and 650 MPa at 1800°C were achieved due to two main microstructural changes. First, rounded SiC particles that were surrounded by a silica-based glass in the as-sintered ceramics evolved into platelets with mostly clean grain boundaries after heat treatment. In addition, the (Hf,W)B 2 solid solution that formed as shells around HfB 2 grain cores during densification reached an equilibrium state after annealing that revealed nano-texturing of the shell, which constituted a nano-composite with metallic W nano-particles embedded within HfB 2 grains. These two features combined to contribute to refractoriness and increased strength at elevated temperature. The unique findings reported in this study launch significant opportunities for ceramic development, manufacturing, and applications.

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