3-D x-ray strain microscopy in two-phase composites at submicron length scales

Abstract

Renewed interest in composite materials is driven by the fact that their mechanical properties can be superior to those of individual constituent phases. Interfaces between the phases and the properties of individual phases are the two key elements responsible for the unique micro-mechanisms of plastic deformation in composites. In this research summary we show how the depth-dependent residual strain distributed in the two phases and partitioned across the composite interfaces can be directly measured at submicron length-scales using x-ray microdiffraction and compared to a detailed simulation within the framework of micromechanical stress analysis. Interface strength is determined from the analysis of the so-called “slip zone” caused by the near-surface stress relaxation. Two examples are discussed: Mo-NiAl and AG-15 composites.