Self-healing effect and oxidation resistance of ZrSiO4-glass coating for C/C composites at 1173 K - 1573 K

ZrSiO4-glass/SiC coatings were prepared on C/C composites by slurry method and their oxidation resistance was investigated by isothermal static oxidation test during 1173–1573 K. The results show that ZrSiO4 is uniformly dispersed and a small amount of quartz crystal is precipitated in the glass. With the increase of oxidation temperature, the weight loss rate decreased gradually to around 0.02% at 1473 K and 0.32% at 1573 K for 10 h. The strength retention increased from 48.4% at 1173 K to 80.3% at 1573 K. The excellent oxidation properties of as-produced coating are may be attributed to self-healing effect of composited glass. The interface bonding strength of the coating/matrix system is 6.06 MPa, and the fracture modes of the samples before and after oxidation belong to pseudo plastic fracture.