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Ni–P(–SiC) composite coatings were successfully deposited on 70 vol% SiCp/Al composite by electroless plating. The surface microstructures and the phase structures of the Ni–P(–SiC) coatings were examined and analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD) before and after heat-treatment at 200–400 °C for 2 h. The thermal diffusivity of the deposited samples and the interface adhesion between the coating and the substrate were investigated. The experimental results show that SiC content in the coatings increases obviously and XRD peaks are enhanced with SiC content in the bath increasing from 3 to 9 g·L−1. After heat-treatment, the surface of the coating becomes smoother and no diffusion layer is produced at the interface. A new phase Ni3P forms in the coating during heat-treatment at 400 °C. The critical load (Lc) of Ni–P–SiC composite coating on SiCp/Al composite reaches the maximum value of 84.9 N with SiC content of 3 g·L−1 after heat-treatment at 200 °C and more or less decreases with the increase in SiC content and heat-treatment temperature. The thermal diffusivity of deposited samples gradually increases as the temperature increases; however, it reduces firstly and then climbs with the increase in SiC content. [ABSTRACT FROM AUTHOR]

Abstract: Silicon carbide (SiC) ceramics were fabricated by plasma-activated sintering. The sintering was accomplished at relatively low temperatures within a short time. The grain growth of the SiC ceramics was considerably inhibited, and finally SiC ceramics with a higher bending strength (853.7MPa) and fracture toughness (8.34MPam1/2) could be fabricated. [Copyright &y& Elsevier]

Abstract: Silicon carbide (SiC) particles coated with nano-boron nitride (BN) were synthesized. The SiC/BN ceramic nano-composites and micro-composites were sintered by plasma-activated sintering. For the nano-composites, due to the homogeneous dispersion of the nano-BN crystals around the SiC grains of the matrix, the grain size of nano-composites was smaller than the monolithic SiC and micro-composites. As a result, the bending strength of the nano-composites decreased slowly (for SiC/20% h-BN nano-composite, about 18% decrease), while their hardness decreased sharply and the machinability properties were improved noticeably. [Copyright &y& Elsevier]

Abstract: An improved film boiling chemical vapor infiltration process was developed to fabricate a large size C/C composite with homogeneous density and microstructure. The C/C composite was prepared by processing a disc-shaped carbon felt preform, whose upper and lower sides were fixed and heated simultaneously by two flat surfaces of two heat sources, with kerosene as a precursor at 1050 °C for 3 h at an atmospheric pressure. The in-situ temperature distribution along the radial direction of the preform upper surface was analyzed to get better information and control of the process. Experimental results show that the average density of the composite of Φ 110×10 mm3 size is about 1.72 g/cm3 and its maximal difference along radial direction is 0.05 g/cm3. Polarized light microscopy (PLM) and scanning electron microscopy (SEM) reveal that the carbon fibers of the composite are surrounded by ring-shaped pyrocarbons with a thickness of ∼20 μm, and that pyrocarbons are delaminated to 4–6 layers. A schematic model is proposed to analyze the process by dividing the reactor into different regions associated with specific functions. [Copyright &y& Elsevier]

Highly porous silicon carbide ceramic with a woodlike microstructure has been prepared by carbothermal reduction reaction of charcoal/silica composites in static argon atmosphere, which were fabricated by infiltrating silica sol into a porous biocarbon template from tilia amurensis wood using a vacuum/pressure infiltration process. The morphology of resulting porous SiC ceramic, as well as the conversion mechanism of wood to porous SiC ceramic, have been investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) techniques. Experimental results show that the biomorphic cellular morphology of tilia amurensis wood charcoal tissue is remained in the porous SiC ceramic with high precision which consists of β-SiC with traces of α-SiC. The strut thickness of resulting SiC ceramic becomes thinner, even partially disappears with the increase of silica amount contained in the charcoal/silica composites. The morphology of the SiC ceramic reveals that solid–solid, gas–solid and gas–gas reactions occurred during the charcoal-to-ceramic conversion. [Copyright &y& Elsevier]

Abstract: AlN particles coated with nano-BN were synthesized. The AlN/BN ceramic composites were sintered by hot-pressing. When the BN content is increased because the nano-BN crystals were homogeneously dispersed around the AlN grains of the matrix, the bending strength of the composites decreased slowly, but the hardness of the composites decreased sharply and the machinability properties were improved noticeably. [Copyright &y& Elsevier]