Improvement in the Self-healing Property of Plasma-Sprayed Environmental Barrier Coatings by SiC Addition

Effect of SiC Content and Particle Size on the Self-Healing Property of Plasma-Sprayed Environmental Barrier Coatings

“…In a previous study, 21) it was reported that a Yb 2 Si 2 O 7 / SiC sintered body using two types of SiC shapes, SiC particles with a specific surface area of 17.16 m 2 /g and SiC whiskers with a specific surface area of 8.47 m 2 /g, showed better self-healing properties when SiC particles with a larger specific surface area were used. The current results of our study are considered valid, as similar results have been also reported 19) for the thermal spray coatings at an oxidation time of 100 h. Next, we focused on SiC content. Comparing Figs.…”

“…Previous studies 10,19) on microstructure control by SiC addition confirmed that new cracks appeared after hightemperature oxidation when the SiC content was 10 wt%. This phenomenon is thought to be due to the excessive volume expansion caused by SiC addition.…”

“…Spraying a mixed powder of Yb 2 Si 2 O 7 and SiC, the problem is the volatilization of the SiO 2 component, which may be produced by the oxidation of SiC due to thermal effects or contained in Yb 2 Si 2 O 7 . 17,18) The previous study 19) showed that using Yb 2 Si 2 O 7 /SiC granulated powder reduces the thermal effect on SiC, suppressing volatilization of the SiO 2 component. The granulated powder is a mixture of several materials in a single particle.…”

Oxidation‐induced crack‐healing behavior of SiC‐Al2O3‐TiB2 composites at 600°C–800°C

“…In the oxidation healing mechanism, some components of the ceramic react with oxygen at a certain temperature to produce volume expansion, and the resulting oxide phase has a certain fluidity to fill and repair cracks, thus greatly restoring material properties. 12,13 Many investigations have been carried out in the past on silicon carbide ceramics, [14][15][16][17][18][19][20] silicon nitride ceramics, [21][22][23] and MAX phase ceramics. [24][25][26][27][28][29][30][31][32][33] These studies have also shown that oxidation mechanism can greatly improve the mechanical properties and service life of the damaged ceramics with better healing effects.…”