A Review on the Development of Prestressed Ceramics

The research of prestressed ceramics which fabricated by introducing the prestress in the surface layer of ceramics is a hot topic in the ceramics field. In this work, the research progresses of preparation method, reinforcing effects and the evaluation of residual stress of prestressed ceramics are summarized. Results indicated that prestressed coating reinforcement method was a simple, low-cost and effective way to strengthen ceramics. By introducing residual compressive stress in the surface layer of ceramics, the fracture energy and impact resistance of brittle materials were improved effectively. That was attributed to the compressive stresses can inhibit crack initiation. Thus the service life of ceramic components was extended. Up to now, this method was applied on architectural ceramics, domestic ceramics, structural ceramics and functional ceramics. According to the reported works, the flexural strength of prestressed Al₂O₃ was increased by about 37%~39% compared to the uncoated Al₂O₃ ceramics. And the pre-stressed ZrO₂ ceramic achieved a flexural strength of 32%~45% higher than that of the common ZrO₂ ceramic. While the prestressed porcelain tiles possess a 50%~102% higher flexural strength than that of uncoated counterpart. For the functional ceramics, prestress strengthening method was applied on the preparation of solid electrolyte successfully. Due to the sufficiently high compressive stress in the surface layer of solid electrolyte, cracks and dendrite penetration were restrained. Hence, a controllable, high-performance and mechanically stable solid electrolyte was obtained. Above all, the reinforcing effects of residual stress on ceramics were significantly effective.

In order to illuminate the strengthening mechanism of prestressed ceramics, indentation deformation was used to understand the effect of residual stress on crack propagation. By comparing the length and the expanded direction of crack in ceramics with and without coating, the form of residual stress was cleared. In addition, the residual stress can also be determined by using relative method.

In general, prestressed coating reinforcement method is a novel and effective preparation technology, which can also be applied in the concrete and the glass fields. The pre-stressing design was universal and has great application prospects.