Plastic-to-brittle transition of saturated, alumina powder compacts

Abstract

Alumina slurries, in which different particle pair potentials were produced by adjusting pH and salt concentration, were used to form cylindrical, consolidated bodies by pressure filtration, at applied pressures between 0.25 and 100 MPa. The mechanical properties of these bodies were investigated by uniaxial compressive loading at a specific rate. Saturated bodies formed from flocced slurries (pH 9) were plastic at low relative densities (<0.54, formed at filtration pressures < 40 MPa) but were brittle (fractured prior to flow) at higher relative densities. Bodies formed from the dispersed slurries (pH 4) were always brittle. When initially stressed, plastic bodies consolidated from the coag..