Experimental and numerical investigation of key microstructural features influencing the localization of plastic deformation in Fe-TiB2 metal matrix composite

A new generation of iron-based matrix composite reinforced by TiB2 particles was deformed in tension to investigate at a mesoscopic scale the localization plastic deformation relation with characteristic microstructural features (in particular, ferrite grain boundaries and particle/matrix interfaces). Large electron back-scattered diffraction (EBSD) maps improved angular resolution were acquired evaluate statistically evolution geometrically necessary dislocation (GND) density from early stage deformation. GNDs found accumulate preferentially matrix/particle interfaces hot-spots located tips elongated particles. Additional length-scale parameters derived EBSD data evidenced key influence two main features: particle morphology clustering. Finally, we present results an advanced full-field micromechanical model that is best suited capture these effects, based on enhanced crystal plasticity elasto-viscoplastic Fast Fourier Transform (EVP-FFT) formulation coupled phenomenological continuum Mesoscale Field Dislocation Mechanics (MFDM) theory. By taking experimental distribution into account, describes qualitatively observed effect morphological heterogenous GNDs.