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Abstract: ZrB2–SiC–Si/B-modified SiC coating was prepared on the surface of carbon/carbon (C/C) composites by two-step pack cementation. The coating could efficiently provide protection for C/C composites from oxidation and ablation. The improvement of oxidation resistance was attributed to the self-sealing property of the multilayer coating. A dense glassy oxide layer could afford the high temperature up to 2573K and efficiently protect C/C composites from ablation. [Copyright &y& Elsevier]

Abstract: A MoSi2–CrSi2–Si/B-modified SiC coating was prepared by two-step pack cementation. The coating could protect C/C composites from oxidation at 1173K for 600min and at 1873K for 300h and from erosion at 1873K for 50h, respectively. B2O3 oxidised from B-modified SiC layer could seal cracks at intermediate temperatures, resulting in improving the oxidation resistance of the coating. Large cracks caused by the bending of the coated specimens and excessive local stress resulted in the fracture of the tested specimens. [Copyright &y& Elsevier]

Abstract: To extend the oxidation protective temperature range of coating for carbon/carbon (C/C) composites, a SiC/ZrB2–SiC/SiC multilayer coating was prepared by a three-step method of pack cementation, slurry and chemical vapor deposition. The prepared coating is composed of three layers with about 150μm in thickness. It can protect C/C composites from oxidation for more than 300h at 1173K which is attributed to the oxidation ability of ZrB2. The coating can also effectively protect C/C composites from oxidation at 1773K for 217h which is due to the SiO2–ZrSiO4 compound glass during oxidation test. [Copyright &y& Elsevier]

Abstract: A MoSi2–CrSi2–SiC–Si multi-component coating was prepared on the surface of carbon/carbon (C/C) composites by a two-step pack cementation method. The microstructure, oxidation behavior and mechanical properties of the coating were studied. These results show that the multi-component coating could protect the C/C composites from oxidation in air at 1873K for 300h and withstand 30 thermal cycles between 1873K and room temperature, respectively. The mass loss and mechanical property loss of the coated C/C composites are considered due to the worse fluidity of SiO2 at intermediate temperatures and the thermal mismatch between the coating and C/C composites. [Copyright &y& Elsevier]

Abstract: To protect carbon/carbon (C/C) composites against oxidation, a Si–Mo coating was prepared on C/SiC-coated C/C composites by a simple slurry method. The microstructure of the coating was characterized by X-ray diffraction, scanning electron microscopy and Raman spectra. Results showed that the coating was mainly composed of SiC, MoSi2 and Si. It could protect C/C composites from oxidation at 1873K in air for 300h and withstand 13 thermal cycles between room temperature and 1873K. The excellent oxidation and thermal shock resistance of the coating was attributed to the formation of dense SiO2 glass at high temperature. The volatilization of MoO3 and SiO2 at 1873K was the main reason of the weight loss of the coated C/C composites. [Copyright &y& Elsevier]

Abstract: Multi-layer MoSi2–CrSi2–Si anti-oxidation coatings with different compositional ratios were prepared on the surface of SiC coated carbon/carbon (C/C) composites by a two-step pack cementation method. The microstructure and anti-oxidation performance of the coating were studied. The results show that the multi-layered coatings could protect the C/C composites from oxidation in air at 1773K for 1000h or 1873K for 750h, respectively. The anti-oxidation performance of the multi-layer MoSi2–CrSi2–Si coating is mainly attributed to their dense and microcrack-free structure, appropriate thermal expansion coefficient and the well dispersed MoSi2 and CrSi2 in the coating. [Copyright &y& Elsevier]

Abstract: To protect carbon/carbon (C/C) composites against oxidation, a SiC nanowire-toughened MoSi2–SiC coating was prepared on them using a two-step technique of chemical vapor deposition and pack cementation. SiC nanowires obtained by chemical vapor deposition were distributed random-orientedly on C/C substrates and MoSi2–SiC was filled in the holes of SiC nanowire layer to form a dense coating. After introduction of SiC nanowires, the size of the cracks in MoSi2–SiC coating decreased from 18±2.3 to 6±1.7μm, and the weight loss of the coated C/C samples decreased from 4.53% to 1.78% after oxidation in air at 1500°C for 110h. [Copyright &y& Elsevier]

Abstract: A C/SiC/Mo–Si–Cr multilayer coating for carbon/carbon (C/C) composites against oxidation at high temperature was prepared by pack cementation and slurry method. Oxidation test results showed that the coating could protect C/C composites from oxidation at 1873K in air for 300h and withstand 40 thermal cycles between 1873K and room temperature. The coating remained intact during the two kinds of tests and no obvious failure was found. The good oxidation and thermal shock resistance of the coating is attributed mainly to the formation of dense glass film on the coating during the oxidation test. [Copyright &y& Elsevier]

Abstract: A C/SiC oxidation resistance coating was prepared on carbon/carbon (C/C) composites by slurry and pack cementation. The microstructure, oxidation resistance and mechanical properties of C/SiC coating prepared from 1773 to 2573K were investigated. With the increase of the preparation temperature, the oxidation resistance of C/SiC coating increases, however, the flexure strength decreases gradually. The preparation of C/SiC coating on C/C composites results in the fracture behavior of C/C composites changing from pseudo-plastic to brittle failure model. The decrease of flexure strength is mainly attributed to the decrease of C/C matrix’ flexure strength at high temperature. [Copyright &y& Elsevier]