Oxidation pre-treatment to improve the mechanical property and oxidation resistance of Si–Mo–Cr coated C/C composites

Carbon nanotube-toughened interlocking buffer layer to improve the adhesion strength and thermal shock resistance of SiC coating for C/C–ZrC–SiC composites

“…Constructing a transition layer with an inlaid structure by pre-oxidation treatment has been proved to be a feasible way to improve the bonding strength between the SiC coating and C/C composites [13]. However, challenge still remains due to the existence of the mismatch of CTEs at the SiC/C interface.…”

Pre-ablation treatment of carbon/carbon composites to improve the thermal shock resistance for SiC coating under oxyacetylene torch

“…Fig.5(c) shows the cross-section image of the SiC coated C/C composites with pre-ablation treatment for 30 s. It can be observed that the infiltration depth of coating materials grows deeper, resulting in the formation of an inter-lock structure. In addition, compared with the interface structure in Fig.5 (a) and Fig.5 (b), the phase interface between coating and C/C substrate also increases, which is helpful to alleviate the mismatch of thermal expansion coefficient between coating and substrate [18]. As for the C/C composites pre-ablated for 45 s (Fig.5(d)), the thickness of SiC coating increases to about 340 μm.…”

“…Compared with Fig.6 (a-c), the thickness of SiC coating reaches the maximum value with the pre-ablation time of 45 s. During thermal shock under oxyacetylene torch, the coated samples were fixed in a water cooled concave (Fig.1), resulting in the formation of a high cooling rate when cooled down. Owing to the high cooling rate and the mismatch of thermal expansion coefficient between coating and C/C substrate the coating would suffer from a pull-stress [18], which could result in the generating of penetrating cracks in the brittle ceramic coating materials ( Fig.6 (d)). …”

“…A preferential interlocking transition layer can be achieved with the help of surface modification, which roughens the surface of C/C substrate before the preparation of coatings [18].…”

Long-term oxidation behavior of carbon/carbon composites with a SiC/B4C–B2O3–SiO2–Al2O3 coating at low and medium temperatures

“…At high temperatures from 1300 to 1630°C, multi-composition coatings with silicon-containing ceramics such as molybdenum disilicide (MoSi 2 ), chromium disilicide (CrSi 2 ), silicate (Y x SiO y ) (or yttrium oxide (Y 2 O 3 )), mullite (3Al 2 O 3 Á2SiO 2 ) and silicon carbide (SiC) are the most promising candidates for protecting C/C composites for long time in an static oxidation environment [2,[5][6][7][8][9][10][11]. A MoSi 2 /SiC coating, fabricated by Huang et al [5] through a hydrothermal electrophoretic deposition technique, can protect C/C composites from oxidation at 1773 K for 346 h with a weight loss of 2.49 mg cm À2 and at 1903 K for 88 h with a weight loss of 5.68 mg cm À2 .…”