抄録
CrB2 obtained by the solid state reaction of chromium and boron could not be sintered even at high temperatures without being applied pressure, but it has been sintered by hot-pressing at about 1700°C. The pressureless and pressure sinterings of Cr-B (atomic ratio 1:2) mixed powder produced by mechanochemical processes were studied. These reactive sinterings were enhanced by the exthothermic heat of reaction of the unreacted Cr-B (1:2) mixture. Mechanochemical effects on the sinterability are interpretted by a negative factor, i.e., a decrease in the reaction heal which predominates the pressure sintering, and a positive factor, a pulverization of the mixed powders which predominates the pressureless sintering with grinding time. The optimum experimental conditions of the pressureless sintering were 30h and 1800°C for grinding time and sintering temperature, respectively, whereas those of the pressure sintering were 10h and 1500°C for grinding time and sintering temperature, respectively.
