|About this Abstract
||2020 TMS Annual Meeting & Exhibition
||Characterization of Minerals, Metals and Materials
||Unloading Analysis for Indentation Fracture in Molecular Crystals
||Alexandra Burch, John Yeager, David Bahr
|On-Site Speaker (Planned)
Nanoindentation can be a highly useful resource in characterization of single molecular crystals such as pharmaceuticals and explosives, materials which are often prone to brittle facture. Fracture events during mechanical testing can render results inaccurate and unusable, so it can be helpful to anticipate the fracture behavior of the material under certain loading conditions. For the first time, a technique has been applied to these classes of materials in which nanoindentation is performed with probes of varying acuity, and the resultant unloading traces of the load-depth curves are compared for superimposability or lack thereof. This indicates the occurrence of radial fracture as a result of indentation. This technique has shown that the explosive HMX has an indentation fracture threshold between 4-8 mN, and the pharmaceutical idoxuridine has a threshold between 100-300 mN.