Carbon-doping Activated Sintering of B_4C Powders Obtained by Jet Milling

Studies on carbon-doping activated sintering of B4C powders with a specific surface area of 2.53m2/g obtained by jet milling were carried out. The effects of carbon-doping agent, carbon-doping content, and specific surface area on B4C sintering density were also studied. The results show that carbon-doping promotes greatly the densification of B4C. Among three carbon-doping agents such as black carbon, glucose, and phenolic resin, the addition of phenolic resin makes B4C reach a highest sintering density, with an optimum carbon-doping content of 3%-5%C. The relative density of B4C is 92.1%TD when sintered at 2200℃ for 1h, and 94.4%TD at 2250℃. If the vibratory milled B4C powders with a specific surface area of 8.30m2/g are used, the density of B4C sintered at 2200℃ increases to 95.6%TD.