Effect of the Spherical Indenter Tip Assumption on the Initial Plastic Yield Stress

摘要: Nanoindentation is widely used to explore the mechanical properties of small volumes materials. For crystalline materials, there a growing experimental and theoretical interest in pop-in events, which are sudden displacement-burst excursions during load-controlled nanoindentation relatively dislocation-free metals. The first event often identified as initiation dislocation nucleation, thus transition from purely elastic elastic/plastic deformation. maximum shear stress at this event, or onset plastic yielding, generally found be close strength material frequently estimated Hertzian contact theory. However, an irregular indenter tip shape will significantly change distribution magnitude location, therefore stress, estimation. aim chapter state challenges limitations for extracting initial yield with spherical assumption. We assess possible errors pitfalls estimation nanoscale.