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Particle erosion of C/C-SiC composites prepared by reactive melt infiltration with different Al addition was studied by gas-entrained solid particle impingement test. SEM, EDS and XRD were performed to analyze the composites before and after erosion. The results indicate that a U shape relationship curve presents between the erosion rates and Al content, and the lowest erosion rate occurs at 40 wt% Al. Except for the important influence of compactness, the increasing soft Al mixed with reactive SiC, namely the mixture located between carbon and residual Si also, plays a key role in the erosion of the C/C-SiC composites through crack deflection, plastic deformation and bonding cracked Si.

In a continuous casting process, mould powder is typically adopted to cover molten steel, which prevents liquid steel from oxidation by air, preserves heat for the top layer of liquid steel, lubricates the initial shell and so on. However, mould powder may deteriorate the quality of the final product if the entrapment of mould powder forms, which is usually caused by the instability of the steel/slag interface. In the current work, a model to predict the critical point of interfacial instability for liquid–liquid stratified flow was developed based on the Kelvin–Helmholtz instability. To prove the validity of the prediction model, a water model experiment was carried out in a rectangular container. In this experiment, oil and water were used to simulate slag and molten steel respectively. The results of the water model prove that the prediction model is correct. Applying the prediction model to a steel–slag system, the critical velocity of molten steel for mould powder entrapment is 0.463–0.541 m s− 1. Wh...

Ba0.2Sr0.8Co0.9Nb0.1O3-δ(BSCN0.2)-xGd0.1Ce0.9O1.95(GDC) (x = 10, 20, 30 and 40 wt.%) composite cathodes were investigated for the potential application in the IT-SOFCs. The results of chemical compatibility measurement show that a small number of Gd and/or Ce ions may melt into the lattice of BSCN0.2 to form BSCN0.2-GDC solid solution. Thermal expansion coefficients effectively reduced by the incorporation of GDC. The electrochemical performance of BSCN0.2-xGDC composite cathodes increased with increasing x from 10 to 30 wt.%. When x = 30 wt.%, the area specific resistances were only 0.040 and 0.017 Ω cm2at 750 and 800oC, respectively. This improved electrochemical performance is attributed to the good thermal expansion match between BSCN0.2-xGDC composite cathode and GDC electrolyte, and the increased oxygen vacancy concentration. With further increasing x, the electrochemical performance of the composite cathode decreased. This result may be due to the ambipolar resistance model of porous composite cathode and the poor electrical conductivity of BSCN-40GDC. The maximum power densities of a BSCN0.2-30GDC/La0.9Sr0.1Ga0.8Mg0.2O3-δ/NiO-Sm0.2Ce0.8O1.9single-cell achieve 537 and 722 mW cm-2at 750oC and 800oC, respectively. These results indicate that the BSCN0.2-30GDC composite cathode is a promising candidate for IT-SOFC.

Bioactive calcium phosphate coatings were deposited on carbon/carbon（C/C） composites using electrochemical deposition technique. The effects of electrolyte concentration and constant current density on morphology, structure and composition of the coating were systematically investigated using scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transformed infrared (FTIR) spectroscopy. The results show that, the coating weight elevated gradually with the increase of electrolyte concentration, and the morphology of coatings changed from spherical particles to nanolamellar crystals with interlocking structure initially. Then the coating transformed into seaweed-like and nano/micro-sized crystals along the depth direction of the coating. The coatings showed seaweed-like morphology as the deposition current density was less than 20mA. With the less current density, the coating became more homogenous. However, the coating was fiakiness crysal, with needlike crystal stacked upside as the current density reached to 20mA/cm2. The coating weight was improved gradually when the current density increased from 2.5mA/cm2 to 10mA/cm2, then reduced with the increasing current density in the range of 10 to 20mA/cm2.

In order to investigate the biotribology behavior of a novel artificial joint pair composed of a carbon/carbon composite femoral head and an ultra-high molecular weight polyethylene (UHMWPE) acetabular cup, a hip joint simulator was employed to predict the clinical wear behavior with a constant load and a lubricant of newborn calf serum. The worn surface and the wear particles generated were analyzed by scanning electron microscopy and laser particle size analyzer. The results showed that the worn surface of UHMWPE had a ripple-like morphology with plentiful furrows. The wear particles generated had various morphologies with a size concentrated at about 15 μm.

In this paper, three kinds of modification coating were prepared to improve wettability of barium–aluminium–silicate glass on carbon/carbon (C/C) composites. The SiC coating was prepared by pack cementation; Cr3C2 and ternary Cr–Si–C coatings were prepared by evaporation reaction process. Contact angles of glass on modified C/C composites were measured at different temperatures by sessile drop technique. Microstructures and morphologies of the wetting interface were determined by scanning electron microscopy, X‐ray diffraction and energy dispersive spectroscopy. Wetting experimental results revealed that barium–aluminium–silicate glass failed to wet the surface of pure C/C composites, but wettability of molten glass on C/C composites clearly improved by surface coating modification. Cr3C2 and Cr–Si–C coatings have a better wettability with glass than SiC coating. Cr–Si–C coating shows the best wettability with barium–aluminium–silicate glass, and the contact angle between them can be reduced to on...

In order to improve the biocompatibility of carbon/carbon(C/C) composites used for hip prosthesis, pyrolytic carbon coating was prepared on their surface by chemical vapor deposition. The microstructures of the samples were analyzed by scanning electron microscopy (SEM) and the biomedical response was assessed by the morphology and proliferation of MG63 osteoblast-like cells. The results show that the texture on the surface of C/C composites changes from chaotic structure to uniform state after the pyrolytic carbon coating is prepared. Osteoblasts cultured on pyrolytic carbon coating present flat shape with thin thickness, and display better proliferation in comparison with those on the uncoated C/C composites surface.