Superplastic forging procedures for manufacture of ceramic yttria stabilised tetragonal zirconia products

Abstract

The influence of initial grain size and density on the deformation behaviour of fine grained yttria stabilised tetragonal zirconia (YTZ) polycrystals has been studied. The presence of very fine (0·2–0·25 μm) grains at the start of straining, together with appreciable initial porosity, leads to an increase in the formability of these usually brittle ceramics. As a result, relatively high strains can be applied at sufficiently low temperatures and high strain rates, such that products of complex shape can be manufactured from YTZ compacts.