Reliability of alumina ceramics. 2: Effect of processing

In this paper an attempt is made to review the mechanical properties that can currently be achieved with the best alumina powders available by utilizing a series of simple processing strategies and surface preparation techniques. The processing techniques include cold-isostatic pressing, slip casting, settling and centrifuging as well as hot-isostatic pressing of as-sintered alumina samples. The surface preparation techniques include grinding and polishing as well as annealing and grinding in the green state. While the fracture strength can be increased from 460 MPa for cold-isostatic pressing to 925 MPa for a centrifuged and cast alumina slip, the Weibull modulus remained between 8 and 12 for most processing strategies. (C) 1997 Elsevier Science Limited. All rights reserved