Growth and coalescence of non-spherical voids in metals deformed at elevated temperature

Void growth and coalescence in ductile materials deformed at elevated temperatures is analyzed by finite element calculations and by an analytical approach. The void growth model is based on an extension of Gursonʹs model to elastic–viscoplastic materials. Coalescence is treated as transition to uniaxial straining in the intervoid ligament by micromechanical analysis. A very simple closed form for the stress in the intervoid ligament at coalescence is given. This closes the micromechanical analysis. Finally, a heuristic estimate (based on the finite element analysis) for the overall strain at void coalesce is given.