On the Linking-Up of Microcracks in Creeping Polycrystals with Grain Boundary Cavitation and Sliding

Abstract

The development of inteigranular creep fracture in metals at elevated temperatures is studied in terms of a planar model analysis. Free grain boundary sliding and grain boundary cavitation is accounted for at all grain boundary facets, including continuous cavity nucleation and growth of cavities by diffusion and creep, while the grains deform by power law creep. The creep rupture process is modelled from the early stage on, where a few cavities have formed, until final failure by link-up of small microcracks resulting from cavity coalescence.