Abstract
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.
