Damage evolution and anisotropy in freeze cast metal/ceramic composites: An in-situ SEM analysis

INTRODUCTION Innovative metal/ceramic composites produced by melt infiltration of innovative ceramic preforms prepared by a freeze casting technique are examined in this study. These composites exhibit a characteristic hierarchical structure: On a mesoscopic length scale, lamellar domains with sizes up to several millimetres are observed (Fig. 1). The aim of the present study is to analyze the elastic and elastic-plastic behavior of the composite at domain levels. In-situ SEM analysis is carried out to investigate the damage evolution under compressive load. Results show that the individual domains exhibit pronounced anisotropy in their mechanical properties, giving rise to stress concentrations and preferred damage nucleation at domain boundaries.