Our website is currently undergoing maintenance. Article records and full texts remain available. Submissions can be made through the Editorial Manager.

In-Situ Synthesis of ZrB₂-SiC Composite Powders: A Review of Processing-Sintering Relationships

Yutong Niu

Journal of Ceramic Science and Technology, Vol. 17, No. 2 (2026), pp. 107-120

DOI: 10.4416/JCST2025-00025

Download full article (PDF)

Abstract

Zirconium diboride-silicon carbide (ZrB2-SiC) composites are leading candidates for ultra-high temperature applications due to their exceptional thermal, mechanical, and oxidation resistance properties. This review critically analyzes in-situ synthesis strategies – namely boro/carbothermal reduction, self-propagating high-temperature synthesis (SHS), sol-gel, and polymer-derived ceramic (PDC) routes – and their impact on powder morphology, phase homogeneity, and sintering behavior. Each method presents a distinct trade-off between scalability, purity, and nanostructural control. The subsequent consolidation techniques, including hot pressing, spark plasma sintering (SPS), and pressureless sintering, are evaluated in terms of their ability to preserve the fine features of the synthesized powders. Particular attention is paid to the influence of sintering aids, grain growth inhibitors, and reactive sintering in achieving dense, defect-free microstructures. The review highlights how synthesis-sintering integration, particularly leveraging rapid consolidation techniques, governs critical performance metrics such as maximum reported hardness (up to 23 GPa) and fracture toughness (exceeding 6 MPa·m¹/²). Specifically, these benchmark properties, for instance, a hardness of 22.7 ± 1.4 GPa and a fracture toughness of 6.3 ± 0.3 MPa·m¹/², are achieved with highly integrated processes such as Reactive Spark Plasma Sintering (R-SPS) of ZrC/B4C/Si precursors, which optimizes phase homogeneity and microstructural refinement for superior performance, and oxidation behavior above 1 500 °C. Key microstructural determinants – such as SiC distribution and residual porosity -are discussed in relation to crack deflection, thermal shock resistance, and borosilicate glass layer formation. The work concludes by identifying the main scientific and technological barriers to industrial adoption, notably oxygen contamination, agglomeration, and process scalability, and proposes future research pathways to enable the next generation of UHTC systems.

Keywords

Nanostructure control, densification techniques, phase purity, thermal degradation, fracture mechanics

View this issue · Article & DOI index