NANOSCALE COMPRESSIVE DEFORMATION MECHANISMS AND YIELD PROPERTIES OF HYDRATED BONE EXTRACELLULAR MATRIX

摘要

Bone features a hierarchical architecture combining antagonistic properties like toughness and strength. In order to better understand the mechanisms leading to this advantageous combination of properties, its postyield and failure behavior was analyzed on the length scale of a single lamella. Micropillars were compressed to large strains in saline solution to measure their anisotropic yield and post-yield behavior under near-physiological conditions. An increase in strength compared to the macroscale by a factor of 1.55 was observed in line with theory for size effects in quasi-brittle materials. Furthermore, a clear influence of hydration with a reduction by 60% compared to in vacuo results was found. This is well in line with literature nanoindentation data and the known change in properties of the organic phase upon hydration.