Papers by Keyword: In Situ Nanoindentation

Abstract: In this work, correlation between nanomechanical properties and crystallographic orientation of grains in 99.9 % magnesium is presented. Crystallographic orientation of individual grains was obtained by scanning electron microscope (SEM) equipped with electron backscatter diffraction (EBSD) detector. Hardness and elastic modulus of grains with known orientation were subsequently determined by in situ nanoindentation in SEM. We show that hardness decreases with increasing angle between the direction of indentation and the c-axis of grains, while elastic modulus varies non-monotonically.

Abstract: Deformation behavior in the vicinity of grain boundary in Fe-0.4wt%C tempered martensitic steel were studied through in-situ nanoindentation in a TEM. Two types of boundaries were imaged in the dislocated martensitic structure: a low-angle lath boundary and a high-angle block boundary. In the case of a low-angle grain boundary, the dislocations induced by the indenter piled up against the boundary. As the indenter penetrated further, a critical stress appears to have been reached and a high density of dislocations was suddenly emitted on the far side of the grain boundary into the adjacent grain. In the case of the high-angle grain boundary, the numerous dislocations that were produced by the indentation were simply absorbed into the boundary, with no indication of pile-up or the transmission of strain.