# Advanced Ceramics with Dual Functions of Healing and Decomposition

## TL;DR

This paper introduces a new ceramic material that can self-heal under steam and decompose under air, both at 400°C.

## Contribution

The novelty lies in creating a ceramic with dual functions of healing and decomposition using metastable products from superheated steam.

## Key findings

- The ceramic composite showed complete strength recovery after one hour in superheated steam at 400°C.
- The same material exhibited decomposition behavior after one hour in air at 400°C.
- XRD analysis confirmed monoclinic ZrO2 as the final product under both conditions.

## Abstract

This study developed advanced ceramic materials with both healing and decomposition functions using a metastable product generated under superheated steam. The developed composite material comprises ZrC particles dispersed in a yttria-stabilized zirconia (YSZ) matrix. After introducing a surface crack of approximately 120 μm on the composite specimen, it showed a complete strength recovery rate after one hour of heat treatment under superheated steam at 400 °C, while it exhibited a decomposition behavior after one hour of heat treatment in air at 400 °C. The XRD analysis of the heat-treated specimens showed that the final product was monoclinic ZrO2 under both steam and air conditions. In other words, full strength recovery in superheated steam was achieved by a chain reaction involving metastable intermediate products derived from H2O, unlike the reaction in air.