Three-Dimensional Investigation of Void Growth Leading to Fracture in Commercially Pure Titanium

The fracture process of commercially pure titanium was visualized in model materials containing artificial holes. These model materials were fabricated using a femtosecond laser coupled with a diffusion bonding technique to obtain voids in the interior of titanium samples. Changes in voids dimensions during in-situ straining were recorded in three dimensions using x-ray computed tomography. Void growth obtained experimentally was compared with analytical model. The model predicted well void growth. Behavior between voids was justified in terms of grain orientation. Depending on the number of grains between voids and the grains orientation, two types of fracture behaviors were observed: i) brittle fracture when grains were in a hard orientation and when few grains were present between voids; ii) ductile fracture when grains were in a soft orientation and when several grains were present between voids.