DISPERSIBILITY OF SIC WHISKERS IN SEVERAL ORGANIC-SOLVENTS

As fundamental research to raise the strength and fracture toughness o f ceramics, the dispersibility of SIC whiskers, W(A), and carbon-coate d SiC whiskers, W(AC), in eight organic solvents was evaluated by meas uring the zeta potential and sedimentation velocity. Ethanol and a-pro panol were selected from these organic solvents, and the dispersibilit y was studied in detail. The electric charge of W(A) was positive in e thanol and negative in 2-propanol. On the other hand, the charge of W( AC) was negative in both solvents. The charge of their whiskers was a minimum (negative) by the addition of 0.001-0.002 g/l dispersant for W (A) and 0.0002-0.001 g/l for W(AC). The dispersibility of W(AC) was wo rse than that of W(A) in ethanol. The dispersibility of both SiC whisk ers was improved by the addition of the dispersant to ethanol and 2-pr opanol. It was estimated that the dispersibility of W(A) and W(AC) was considerably affected by steric hindrance of the polymer used as a di spersant.