Comminution of silicon carbide powder in a planetary mill

Silicon carbide powder (SiC) was comminuted in a planetary mill during time intervals of 0.5, 2, 4 and 6 h. The wet milling media was ZrO2 spheres in isopropyl alcohol. The powders were then characterized with respect to chemical composition, particle size distribution, surface area and density for each milling time. The average particle size was reduced from 1.8 μm to 0.4 μm in 30 min and the amount of ZrO2 increased linearly with milling time. The result was a homogeneous combination of submicrometer and nanometric SiC + ZrO2 powder, which possessed good sinterability in liquid phase and high fracture toughness.