Kinematic Strain Hardening of Fe-TiB2 Composite: Experimental Analysis and Phenomenological Modeling

A combined experimental and modeling study of strain hardening and backstresses of an iron-based Metal Matrix Composite MMC (Fe-TiB2) is presented. New quantitative data related to the kinematic hardening of this industrially challenging composite have been obtained via reverse shear tests up to large plastic stains. As the data show an increasing contribution of the kinematic hardening with both TiB2 reinforcement effect and solid solution in ferritic matrix, the relevance of existing phenomenological models of work hardening for automotive steels for the description of the behavior of this steel-based MMC has been tested. This model based on the extended KME hardening model validated by Bouaziz et al. (JMPT 106:5–67, 2000) for ferritic steels and a standard mixture laws between particles and matrix, succeeds in reproducing the overall stress–strain of this MMC from phase constituents from the use of fixed set of physically based parameters for ferrite and a small number of additional ones. Good agreement is found between the computed and measured backstresses. The model, despite its phenomenological character and although it is limited to a one-dimensional approach, provides a reliable estimation of particles fracture stress, suggesting thus its efficiency to predict and model steel-based materials with increasing microstructural complexity and contents.