Gallagher, Hugh G.Sherwood, John N.Vrcelj, Ranko2021-12-202021-12-202021-10-20Gallagher HG, Sherwood JN, Vrcelj RM. (2021) Microhardness indentation studies of 2-4-6 trinitrotoluene. Propellants, Explosives, Pyrotechnics, Volume 46, Issue 11, November 2021, pp. 1733-17390721-3115https://doi.org/10.1002/prep.202100132http://dspace.lib.cranfield.ac.uk/handle/1826/17345The microhardness of the {001} faces of 2-4-6 trinitrotoluene crystals has been investigated using both Vickers and Knoop indentation methods. The Vickers hardness number was found to be 22.5 kg mm−2 independent of crystal orientation and perfection. At ambient temperatures (∼20 °C) the Knoop hardness number varied between 20.5 kg mm−2 and 24.0 kg mm−2 with crystal orientation. At higher temperature (50 °C) the Knoop hardness anisotropy curve retained its shape, although the overall hardness decreased by 10 %. We interpret this change as reflecting a simple temperature dependant loosening of the crystal lattice rather than any change in deformation mechanism. No variation of Knoop hardness was evident with changing load. The hard direction was [010] and the soft [100]. The dominant operative slip system was defined to be {001}[010].enAttribution-NonCommercial 4.0 Internationalhttp://creativecommons.org/licenses/by-nc/4.0/Mechanical propertiesTNTMicrohardnessArticle