Characterization and modeling of the damage mechanisms in ductile steel metal-matrix composites: Application to virtual forming

The aim of this work is to investigate the damage mechanisms and stiffness loss in Fe-TiB2 metal-matrix composites during plastic deformation. First, experimental results of interrupted tensile tests are performed to quantify the evolution of damage, using SEM observations, as well as the decrease of Young's modulus as a function of the tensile strain. The experimental results are then used to calibrate a two-step homogenization model for metal-matrix composites in which the nucleation and growth of voids modify incrementally the overall elastic properties. The model is finally applied to the numerical prediction of stiffness loss in a problem of metal forming based on Nakazima tests. Overall, the stiffness loss predicted before the onset of coalescence is moderate and its distribution is homogeneous, emphasizing that Fe-TiB2 metal-matrix composites could be used in applications requiring metal forming.