Enhanced oxidation resistance of HfB₂‐SiC‐ZrSi₂ coating at 1700°C through low‐loss film‐forming treatment

Abstract

To enhance the oxidation resistance of HfB2‐SiC‐ZrSi2 coating, low‐loss film‐forming treatment (LFT) was employed to generate high‐quality oxygen barrier glass layers, and the modification effect of varying formation temperature on the oxidation resistance was investigated at 1700°C. The results demonstrated that, with LFT at 1500°C, the relatively modest oxidation activity and complete dispersion of metal oxide nanocrystals generated a compact and continuous composite glass layer, which caused a decreased oxidation activity at 1700°C. The excessive formation temperature might result in oxidized and porous coatings, while lower temperatures could lead to poor fluidity of the glass layer, rendering it challenging to achieve compact composite glass layers. The coating sample with LFT at 1500°C exhibited a carbon loss rate of 0.33 × 10−6 g·cm−2·s−1 and an oxygen permeability level of 0.28%, respectively, when oxidized at 1700°C. These results provide fundamental insights into the oxidation resistance mechanisms within the modified HfB2‐SiC‐ZrSi2 coating system.