Ceramics and composites are the load-bearing, heat-taking and ion-conducting materials class where 2026 research is moving from single-property optimisation to compositional complexity, engineered interfaces and simulation-led design, with a handful of hard experimental results (a plasma-sprayed zirconia coating surviving near 3200 °C ablation, diamond/cBN composites tested at Mach 8.45) and a much larger body of computational work behind them.
Summary
“Ceramics and composites” covers materials held together by ionic or covalent bonds (oxides, carbides, nitrides) and multi-phase systems that combine a matrix with reinforcement (fibre-reinforced polymers, ceramic matrix composites, nanocomposites). They are chosen where metals fail: above roughly 1000 °C, under oxidation and ablation, as electrical insulators or ion conductors, and where stiffness per unit mass matters. The historic weakness is brittleness and process sensitivity, so most of the engineering effort sits in composition, microstructure and interface control rather than in bulk chemistry.
Second, interfaces and processing. Interfacial thermal conductance across Si/SiC and SiC/diamond stacks depends on polytype and on interlayer structure: 4H-SiC couples better to Si than 3C-SiC, and an ultrathin 0.5 nm amorphous SiC layer raised conductance from 613 to 716 MW/m²K by acting as a phonon bridge, while thicker or Si-rich layers degraded it. On the processing side, first-principles work proposes a Fermi-level mechanism for flash sintering in yttria-stabilised zirconia, in which charge compensation of defects cuts the Zr vacancy diffusion barrier by about 2 eV during flash.
Third, extreme-environment performance, which is where the most consequential experimental numbers appear. Ytterbia-stabilised zirconia coatings applied by atmospheric plasma spraying reportedly raised the melting point of ZrO2 to about 2850 °C and withstood plasma and oxyacetylene ablation to roughly 2780 °C and 3200 °C, described as the highest temperature resistance reported. Diamond particles embedded in a cubic boron nitride matrix were impacted by metal projectiles at speeds up to Mach 8.45, with energy absorption traced to a shock-induced diamond-to-graphite phase change. On the composite side, geometry-resolved atomic oxygen modelling for very low Earth orbit predicts a CFRP zenith panel eroding 15.1 to 16.2 µm per year at 350 km despite receiving only a few per cent of ram-facing fluence. The parameters that decide outcomes are therefore: phase stability at temperature, interface structure at the nanometre scale, and whether the processing route that produces the laboratory microstructure is one that industry already runs.
CNT-reinforced polymer composites (added 12 Oct 2026)
CNTs entered composites as a resin additive at low loading, with carbon fibre still carrying the load (Easton/Zyvex sporting goods from 2005, Zyvex’s Piranha boat 2011 ref). NASA’s 2024 lessons-learned: structural applications did not materialise, the payoff was electrical ref. US-COMP CNT-yarn laminates reached strength parity with IM7 and c.2x stiffness, with the yarn/resin interface unsolved ref. Production uses today are conductive, not structural: fuel lines and paintable body panels ref. Detail: Carbon Nanotubes, brief projects/cnt-dispatch/2026-10-12-edition-013-composites-brief.md.
Evidence base
- 8 July 2026: 32 ultrahigh-entropy compositionally complex ceramics with 16 to 19 components were synthesised; 12 of the first 15 formed single fluorite or pyrochlore phases, two showed fluorite-fluorite dual phases for the first time, and an order-disorder transition was located at y ≈ 0.84
- 31 July 2026: plasma-sprayed ytterbia-stabilised zirconia coatings reportedly raised the melting point of ZrO2 to about 2850 °C and withstood plasma and oxyacetylene ablation to nearly 2780 °C and 3200 °C, described as the highest reported temperature resistance
- 21 July 2026: an ultrathin 0.5 nm amorphous SiC interlayer raised Si/3C-SiC interfacial thermal conductance from 613 to 716 MW/m²K, while thicker, silicon-rich or amorphous-Si layers degraded conductance, severely so at SiC/diamond interfaces
- 11 August 2026: diamond particles in a cubic boron nitride matrix were impacted by metal projectiles at up to Mach 8.45, with energy absorption and fracture attributed primarily to shock-induced diamond-to-graphite phase change
- 29 July 2026: geometry-resolved modelling of a 350 km sun-synchronous orbit predicted 6.9 to 7.5 × 10²¹ atoms/cm² annual ram-facing atomic oxygen fluence and 15.1 to 16.2 µm/year erosion of a CFRP zenith panel, reordering component-level risk versus fluence alone
- 28 July 2026: first-principles work attributed flash sintering acceleration in yttria-stabilised zirconia to a Fermi-level shift that cuts the Zr vacancy bulk diffusion barrier by 2 eV, replacing a previously speculative mechanistic picture
- 20 July 2026: ensemble molecular dynamics found a 3 wt% water threshold in epoxy and epoxy-graphene nanocomposites, below which hydration lowers the glass transition temperature but leaves mechanical properties unaffected
Open questions
- Do the YbSZ coatings survive repeated thermal cycling and long-duration exposure, or is the near-3200 °C ablation result a short-duration torch number that spalls in service?
- Does any 16 to 19 component compositionally complex ceramic outperform a five-component or conventionally doped ceramic on a measured property, not just on phase stability?
- Do machine-learned-potential predictions of oxygen diffusion in rare-earth high-entropy oxides match measured ionic conductivity in the same compositions?
- Can a 0.5 nm amorphous SiC interlayer be deposited reproducibly at wafer scale, given that thicker or silicon-rich layers reverse the benefit?
Assessment drafted 2026-08-31 from up to 18 KB sources using the technology-scorecard framework; scores are a draft read pending review.