AUTOCATALYSIS - THE SELF-INDUCED GROWTH OF MARTENSITIC PHASE-TRANSFORMATIONS IN CERAMICS

The phenomenon of autocatalysis, wherein a region of elastic phase tra nsformation creates stresses sufficient to drive alone further transfo rmations, is studied for two specific configurations: a rectangular st rip and an infinite row of equally spaced circular spots. The phenomen on is associated, not exclusively, with dilatational strains triggered by critical levels of maximum in-plane shear stress. The analysis pre dicts that there may be a minimum critical transformation stress level below which spontaneous transformation occurs.