Modeling of cavity coalescence during tensile deformation

Abstract

The effect of material properties such as the cavity growth rate and initial cavity population on cavity coalescence during uniaxial tensile deformation was determined. To this end, a two-dimensional model that treats the growth of a random array of spherical cavities inside a deforming tension specimen was developed. Simulation results included predictions of the conditions under which cavity coalescence occurs, the variation of average cavity radius and fraction of cavities which have coalesced as a function of strain, and the evolution of cavity size distribution as a function of strain, cavity growth rate, and cavity population. For a given cavity density, it was found that the fraction of cavities which has coalesced is independent of the cavity growth rate and varies linearly with the cavity volume fraction; a relationship between the fraction of coalesced cavities and the cavity volume fraction was established from the simulation results. In addition, simulation predictions of average cavity radius as a function of strain were compared to previous relations for cavitation under conditions involving growth and coalescence. Predictions of average cavity size as a function of strain from the present work gave good agreement with previous experimental and theoretical work of Stowell and Pilling.