Methodology for evaluating self-healing agent of structural ceramics

Abstract

Simple methodology for evaluating availability of self-healing agent has been established from the investigation on the relationship between oxidation behavior of self-healing agent and self-healing phenomena. The consistency of the established methodology was discussed by comparison in the lower bound of the available temperature range (T_H-low) of mullite/TiSi₂ composite. From thermo-gravity and differential temperature analysis, the available temperature range for 10-h healing ( $T_{\mathrm{H}-\mathrm{low},10\mathrm{h}}^{\mathrm{est}}$ ) was estimated to be 563°C. On the other hand, the value of the lower bound of the available temperature range for 10-h healing ( $T_{\mathrm{H}-\mathrm{low},10\mathrm{h}}^{\exp }$ ) was experimentally determined to be 600°C from strength recovery tests. These values showed a good consistency. Also, the data on 1-h healing of mullite/TiSi₂ and the reference data on alumina/SiC self-healing ceramics exhibited good consistency. Therefore, the proposed methodology is sufficient for evaluating the advanced healing agent.