Preparation and characteristics of C/C composite brake disc by multi-cylindrical chemical vapor deposition processes

1INTRODUCTION C/Ccompositeisakindofmultifunctioncom posite,whichhasmanyspecialproperties,suchas excellentheat resistantpropertyanddimensional stability,highspecificstrengthandmodulus,as wellaslowthermalexpansioncoefficientandwear rate15].Itistheonlyheat structuralmaterialthat canworkinnon oxygenandattemperatureover1600℃foralongtime.Moreover,itsspecific thermalcapacityistwiceaslargeasthatofcom monmetalmaterialanditsheat conductivitycanbe designedasrequired.Therefore,C/Ccomposite haswide…

Preparation and characteristics of C/C composite brake disc by multi-cylindrical chemical vapor deposition processes

The C/C composite brake discs were prepared by tri-cylindrical chemical vapor deposition (CVD) process. The optimum processing parameters were as follows: deposition temperature was 830-930 ℃, the gas-flow rates of N2 and propylene were 4.8-5.2 m3/h and 5.8-6.2 m3/h, respectively, the furnace pressure was 4.5-5.5 kPa and the deposition time was 200 h.The effects of processing parameters on the densified rates, thermal-physical property and mechanical performance of C/C composite brake discs were studied. The results show that density, heat conductivity, bend strength and abrasion ratio of the multi-cylindrica brake discs are 1.02-1.78 g/cm3, 31 W/(m·K), 114 MPa and 7 μm/s, respectively, which are approximately similar to those of the single-cylindrical ones. The gas flow rate has no relation to the number of the cylinder and furnace loading. The utilization ratio of carbon can be improved by multi-cylinder CVD process without changing the characteristics of brake disc.