Dynamic and Static Grain Growth During the Superplastic Deformation of 3Y-TZP
J Seidensticker, M J. Mayo
While phenomenological theories of superplasticity have often suffered from the fact that a single phenomenological law is not universally applicable to all superplastic systems, it is shown that a universal dynamic grain growth law does apply. The law is explained in terms of a mechanism which involved the sliding of grains into geometrically necessary holes opened up by grain growth. The same mechanism also appears to explain several fundamental aspects of superplasticity. An interesting implication of the proposed dynamic grain growth theory is that normal grain growth should also lead to the kinds of grain-to-grain displacements historically considered the distinguished hallmark of superplasticity. Recent data from sapphire replica tests on yttria-stablized zirconia samples show this is indeed the case.