Abstract
Generally, cavities are formed during superplastic deformations, and they subsequently grow with diffusion and/or plastic-flow or superplastic diffusion controlled mechanisms in metallic superplastic materials. Tensile test specimens of 3mol% yttria stabilized tetragonal zirconia polycrystals (3Y-TZP) were pulled at 1723 K with an initial strain rate of 3.3×(10)^<-4>s^<-1> in the air to nominal strains from 0.0 to 200%. Distributions of cavity number to cavity diameter were obtained by image processing on scanning electron micrographs. We proposed a simulation method to estimate cavity growth rates using data of the distributions. As a result, newly formed cavities grow very rapidly as soon as they nucleated, but their growth become slowly with increasing their size.
