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SiC/SiC composites coated with the pyrolytic carbon (PyC) interphase coatings of different thickness were fabricated by polymer infiltration and pyrolysis (PIP) process using microwave sintering at 1100 °C assisted with the hot mould pressing pressure of 3 MPa. The effects of the PyC coating thickness on the densification, the flexural properties and microstructures of the fabricated SiC/SiC composites were investigated via the mercury intrusion test, the computed tomography (CT) technique and scanning electron microscopy (SEM). The results indicate that the preforms coated with thinner PyC coatings, which have better flexibility under the hot mould pressing process, bring SiC/SiC composites with higher densification degrees, due to their better flexibility under the hot press moulding process. Simultaneously, thicker PyC coatings result in weaker interphase debonding between SiC fibers and matrix quantified by the single fiber push-out test. Too thick or too thin PyC coatings both make against the flexural properties, as they will cause the debonding between SiC fibers and matrix too early or too late. The PyC coating thickness-0.20 μm is approximate for the better flexural properties.

While lithium-ion batteries (LIBs) have been widely used in commercial devices, finding suitable anode materials for alkali metal batteries is still challenging. Therefore, Ni3S2/Ni@N-doped carbon composite electrode was fabricated as the anode for alkali metal batteries. It was found that the Ni3S2/Ni@N-doped carbon electrode achieved a capacity of 742 mAh g−1 at the 1500th cycle at the current density of 1000 mA g−1 for LIBs, and obtained 275 mAh g−1 at the 250th cycle during 500 mA g−1 for Na+ storage. Moreover, it showed 52 mAh g−1 after 50 cycles at 100 mA g−1 for K+ storage. The excellent performances of this electrode is likely due to the combined effect of Ni and C layer. This work provides a simple approach approach for the design of high-performance materials that can be applied to commercial production as a potential substitute for the current alkali ion battery anodes.

SiC/SiC composites were fabricated by polymer impregnation and pyrolysis (PIP) process via microwave and conventional heating at 800 °C, 900 °C, 1000 °C and 1100 °C. The effects of sintering heating types and sintering temperatures on the densification process and pore distributions of the fabricated SiC/SiC composites were studied. The densification processes were discussed in the form of the weight gain rates at each PIP cycle. The pore location distributions were observed by scanning electron microscopy (SEM) and computed tomography (CT) technique. The porosity and pore size distributions were quantified by the mercury intrusion test. The results indicate that lower heating rates and higher sintering temperatures are benefit to the densification of the SiC/SiC composites. But the more micro-cracks generated from higher heating rates of microwave sintering (∼40 °C/min) make the flexural strength and toughness of the SiC/SiC composites higher than that of the conventional sintered ones.