High temperature oxidation of silicon hexaboride ceramics

Influence of iodine concentration on microstructure and oxidation resistance of SiB6–MoSi2 coating deposited by pulse arc discharge deposition

“…According to those reports [6,11,23] and the XRD pattern of SiB 6 -MoSi 2 /SiC coated C/C composites oxidation at different time (Fig. 8), the SiB 6 -MoSi 2 /SiC coated C/C composites mainly undergo the following the six reactions as shown in Eqs.…”

“…9(a), probably due to the escape of the gas phase (such as B 2 O 3 , MoO 3 and SiO). The gas phase generated from the oxidation of SiB 6 , MoSi 2 and SiC on the coating surface and the interface of SiB 6 -MoSi 2 coating and SiC bonding layer by the reaction (8)- (11). The weight loss is attributed to the escape of the gas phase (B 2 O 3 , MoO 3 , CO, SiO and CO 2 ).…”

“…This possibly form from the escape of CO and CO 2 which can be attributed to the oxygen diffuses through the thin glass layer to react with the C/C matrix (Eqs. (12), (13)) [11] and from the frequent thermal shocks between high temperature and room temperature during the isothermal oxidation tests process. The C/C matrix is oxidated (Fig.…”

“…SiB 6 was added in the MoSi 2 based coating as a second phase as the reinforcement materials to improve the oxidation resistance of the coating. SiB 6 has good oxidation protective property and can forme borosilicate glass (including SiO 2 and B 2 O 3 ) at high temperature which not only has good oxidation resistance but also can seal the defects [11,12].…”

Microstructure, radiative property and thermal shock behavior of TaSi2–SiO2-borosilicate glass coating for fibrous ZrO2 ceramic insulation

“…Moreover, on the one hand, TaSi 2 will be oxidized during the sintering process of composite coating; hence, different heat-treatment times were adopted in the preparation process to evaluate the effect of heat-treatment times on the microstructure and the radiation property of the coatings. On the other hand, SiB 6 can form borosilicate glass (including SiO 2 and B 2 O 3 ) at high temperature, which not only has good oxidation resistance but also can seal the defects [45,46]. Thus, both coatings with and without SiB 6 at different heat-treatment times were prepared.…”