Carbon fibre reinforced carbon and SiC dual matrices composites （C/C-SiC） show superior tribological properties,high thermal shock resistance and good abrasive resistance,and they are promising candidates for advanc...Carbon fibre reinforced carbon and SiC dual matrices composites （C/C-SiC） show superior tribological properties,high thermal shock resistance and good abrasive resistance,and they are promising candidates for advanced brake and clutch systems.The microstructure,mechanical properties,friction and wear properties,and application of the C/C-SiC composites fabricated by warm compacted-in situ reaction were introduced.The results indicated that the composites were composed of 50-60 wt pct carbon,2-10 wt pct residual silicon and 30-40 wt pct silicon carbide.The C/C-SiC brake composites exhibited good mechanical properties.The value of flexural strength and compressive strength could reach 160 and 112 MPa,respectively.The impact strength was about 2.5 kJ·m-2.The C/C-SiC brake composites showed excellent tribological performance,including high coefficient of friction （0.38）,good abrasive resistance （1.10 μm/cycle） and brake steadily on dry condition.The tribological properties on wet condition could be mostly maintained.The silicon carbide matrix in C/C-SiC brake composites improved the wear resistance,and the graphite played the lubrication function,and right volume content of graphite was helpful to forming friction film to reduce the wear rate.These results showed that C/C-SiC composites fabricated by warm compacted-in situ reaction had excellent properties for use as brake materials.展开更多
Heat transfer in passage with pin-fin arrays for cooling blade trailing edge was studied numerically. Three-dimensional numerical simulations were carried out for steady laminar flow in passages with different wedge a...Heat transfer in passage with pin-fin arrays for cooling blade trailing edge was studied numerically. Three-dimensional numerical simulations were carried out for steady laminar flow in passages with different wedge angles between pressure surface and suction surface of cooling blade trailing edge to study the effect of different wedge angles (from 0°to 30°) on heat transfer and pressure losses. Research was carried out for both in-line array and staggered array. From this investigation, wedge angle 10°gives the best heat transfer performance.展开更多
基金supported by the National Hi-Tech Research Development Program of China (No.2006AA03Z560)Excellent Youth of Hunan Province,China (No. 06JJ1007)
文摘Carbon fibre reinforced carbon and SiC dual matrices composites （C/C-SiC） show superior tribological properties,high thermal shock resistance and good abrasive resistance,and they are promising candidates for advanced brake and clutch systems.The microstructure,mechanical properties,friction and wear properties,and application of the C/C-SiC composites fabricated by warm compacted-in situ reaction were introduced.The results indicated that the composites were composed of 50-60 wt pct carbon,2-10 wt pct residual silicon and 30-40 wt pct silicon carbide.The C/C-SiC brake composites exhibited good mechanical properties.The value of flexural strength and compressive strength could reach 160 and 112 MPa,respectively.The impact strength was about 2.5 kJ·m-2.The C/C-SiC brake composites showed excellent tribological performance,including high coefficient of friction （0.38）,good abrasive resistance （1.10 μm/cycle） and brake steadily on dry condition.The tribological properties on wet condition could be mostly maintained.The silicon carbide matrix in C/C-SiC brake composites improved the wear resistance,and the graphite played the lubrication function,and right volume content of graphite was helpful to forming friction film to reduce the wear rate.These results showed that C/C-SiC composites fabricated by warm compacted-in situ reaction had excellent properties for use as brake materials.
文摘Heat transfer in passage with pin-fin arrays for cooling blade trailing edge was studied numerically. Three-dimensional numerical simulations were carried out for steady laminar flow in passages with different wedge angles between pressure surface and suction surface of cooling blade trailing edge to study the effect of different wedge angles (from 0°to 30°) on heat transfer and pressure losses. Research was carried out for both in-line array and staggered array. From this investigation, wedge angle 10°gives the best heat transfer performance.
