A void-crack nucleation model for ductile metals

A phenomenological void-crack nucleation model for ductile metals with seco nd phases is described which is motivated from fracture mechanics and micro scale physical observations. The void-crack nucleation model is a function of the fracture toughness of the aggregate material, length scale parameter (taken to be the average size of the second phase particles in the example s shown in this writing), the volume fraction of the second phase, strain l evel, and stress state. These parameters are varied to explore their effect s upon the nucleation and damage rates. Examples of correlating the void-cr ack nucleation model to tension data in the literature illustrate the utili ty of the model for several ductile metals. Furthermore, compression, tensi on, and torsion experiments on a cast Al-Si-Mg alloy were conducted to dete rmine void-crack nucleation rates under different loading conditions. The n ucleation model was then correlated to the cast Al-Si-Mg data as well. (C) 1999 Elsevier Science Ltd. All rights reserved.