Advanced structural ceramics such as oxide ceramics, nitride ceramics, carbide ceramics, and boride ceramics have extensive application in strategic fields, such as semiconductor technology, nuclear energy, aerospace engineering, and marine engineering. This is attributed to their remarkable properties, which encompass superior mechanical properties, low high-temperature creep, resistance to acid and alkali corrosion, and high thermal conductivity. However, the fracture strength of brittle ceramic materials typically exhibits significant discreteness, leading to a reduced reliability. The main reason is that ceramic materials have strong covalent and ionic bonds, poor plasticity at the crack tip, and a low resistance of the lattice to crack propagation, resulting in a large amount of stress concentration at the crack tip and propagation with minimal energy consumption, thus having inherent brittleness. This can result in a catastrophic failure of ceramic material components as undetectable structural defects may initiate and propagate under stress. The reliability issues arising from strength dispersion due to inherent brittleness as well as microcracks and other defects restrict the application of ceramics as engineering structural materials. Based on the urgent needs of engineering applications, the reliability issue of ceramic materials has attracted widespread attention. Therefore, this review summarizes the theoretical basis, evaluation methods, and influencing factors of fracture strength reliability of ceramic materials such as silicon carbide, and discusses the methods for improving the fracture strength reliability of advanced structural ceramics, providing a theoretical guidance for promoting the wider engineering application of ceramic materials. The statistical theory of fracture strength is the theoretical basis for analyzing reliability. There are considerable researches on the statistical properties of fracture strength of ceramic materials, and various fracture strength statistical theories are established. The Weibull statistical theory is a statistical theory based on the principle of “weakest link connection” and a large amount of experimental data that can describe the distribution law of ceramic fracture strength. It is widely used in the field of strength dispersion statistics of brittle materials such as ceramics. With the development of computer technology, numerical simulation methods such as finite element method (FEM), discrete element method (DEM), and discontinuous deformation method (DDA) are used to analyze the damage mechanism and failure process of brittle materials in order to predict material properties and strength distribution. The failure of advanced structural ceramic materials is usually related to the pre-existing defects. The key to improving the reliability of fracture strength lies in enhancing crack propagation resistance and achieving precise control over material defects. This review proposes to enhance the reliability of fracture strength from four aspects, i.e., intrinsic microstructure, toughening microstructure construction, optimization of forming methods, and surface strengthening treatment. The reliability of ceramic materials is strongly correlated with their microstructural characteristics. Tailoring grain size and enhancing microstructural uniformity can substantially improve material reliability. The enhancement of reliability in ceramic materials is inherently linked to the optimization of fracture toughness. Through the rational design of toughening mechanisms that increase crack propagation resistance and significantly reduce strength distribution dispersion, mechanical properties and reliability can be synergistically optimized. Forming technology affects both the uniformity of the green body and the capability to fabricate complex components, thereby directly impacting the reliability of the material. Enhancing surface quality and reducing surface defects through techniques such as polishing, oxidation healing, laser modification, and coating integration serve as an effective approach to improving the reliability of fracture strength.

This review systematically analyzes the theoretical basis, evaluation methods, and improvement methods of fracture strength reliability of advanced structural ceramic materials, which has a certain guiding significance for the study of fracture strength reliability of ceramic material systems exhibiting brittle characteristics. The Weibull theory is widely applied in the statistical field of strength discreteness of brittle materials such as ceramics, and has an irreplaceable engineering value in characterizing the reliability of fracture strength of ceramic materials. The core of improving the reliability of fracture strength of advanced structural ceramic materials lies in enhancing their ability to resist crack propagation and precise control of defects. The reliability of fracture strength can be improved via controlling the uniformity of grain size and microstructure distribution, adding second phases to construct toughening microstructures, optimizing molding processes to reduce the occurrence of defects in the preparation process, and repairing surface defects through secondary treatment. Future reliability research will develop intelligent design and preparation, high purity and uniformity control, biomimetic composite toughening, as well as fine processing and in-situ self-healing.