Bz. Margolin et al., MODELING FOR TRANSCRYSTALLINE AND INTERCRYSTALLINE FRACTURE BY VOID NUCLEATION AND GROWTH, Fatigue & fracture of engineering materials & structures, 21(2), 1998, pp. 123-137
A criterion has been formulated for transcrystalline and intercrystall
ine fracture caused by the evolution of voids located both in a grain
and on grain boundaries. The criterion is based on the idea of plastic
collapse for a unit cell that is a regular structural mezovolume of p
olycrystalline material. The criterion does not require the introducti
on of any empirical parameters, such as critical void size, critical s
ize of ligament between voids and critical void volume fraction, which
are used in most models. Modelling has been performed for void nuclea
tion and growth in a grain and on grain boundaries for elastic-plastic
deformation and under creep conditions. A scheme is proposed to descr
ibe the transition from transcrystalline to intercrystalline cavitatio
n fracture as a function of strain rate and temperature. The effect of
stress triaxiality on the critical strain and the lifetime for both t
ranscrystalline and intercrystalline fracture has been investigated. A
comparison of the results predicted by the suggested criterion with a
vailable empirical data has been performed.