|About this Abstract
||MS&T22: Materials Science & Technology
||Controlled Synthesis, Processing, and Applications of Structural and Functional Nanomaterials
||Eliminating Artifactural Indentation Size Effects in Nanoindentation of Hard Ceramics
||James A. Wollmershauser, Boris Feigelson, John Drazin, Edward Gorzkowski, Heonjune Ryou
|On-Site Speaker (Planned)
||James A. Wollmershauser
Hardness is a ubiquitous characterization tool to measure the worth of ceramics and with the advent of instrumented indentation, use has only increased. However, instrumented indentation, primarily nanoindentation, measures hardness differently than classical methods such as Vickers or Knoop hardness and instrumented indentation habitually provides an inflated hardness value. These inflated hardness values often inversely correlate with indentation depth and the effect is most commonly referred to as indentation size effect (ISE). Oliver & Pharr’s 2004 work refines instrumented indentation calibration and analysis methods, and we show that ISE can be eliminated in fully dense hard ceramics when utilizing their approach. Using magnesium aluminate spinel ceramic samples with grain sizes ranging from ~20 nanometers to ~20 micrometers, we prove that ISE is negligent for contact depths from 20 nanometers to 1 micron. Such an implementation and analysis is critical when determining hardness values for new materials, including superhard and nanomaterials.