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Showing results for tags 'materials'.
Some clever gents gently broke buckyballs "to form a disordered nano-clustered graphene-based hard phase with more than 90% elastic recovery after deformation", a novel amorphous material with extraordinarily high hardness and compressive strength: https://academic.oup.com/nsr/advance-article-pdf/doi/10.1093/nsr/nwab140/39584180/nwab140.pdf From what I can tell this creates layers of graphene-like platelets with enmeshed edges. Now that we know what it looks like, maybe it can be synthesized from graphene rather than buckyballs, for slightly more economical mass production.
I ran across this curious gem today: http://ciar.org/ttk/mbt/papers/misc/paper.x.materials.library_curtin_edu_au.Characterization_of_mechanical_and_fracture_behaviour_in_nano_silicon_carbide_reinforced_vinylester_nanocomposites.2013.alhuthali_low.pdf In it, Alhuthali and Low examine the influence of SiC nanoparticles on vinylester's fracture mechanics. Of particular interest was the discovery of a "sweet spot" in the ratio of vinylester to SiC for maximum strength vs toughness, being somewhere near 5% SiC but definitely higher than 3% and lower than 10%. Also, on pp11-12 it is mentioned that larger SiC granules offer a toughening effect by mitigating crack propagation (like ripstop). Thinking back to previous discussions of ballistic properties of composites of vinylester and large-diameter ceramic granules in closer to 50%/50% proportion, it occurs to me that one might combine the strengthening effect of the nanoparticles with the antiballistic and toughening effects of large-diameter granules. A mixture of 57% vinylester, 3% SiC nanoparticles, and 40% SiC granules would put the fraction of nanoparticles in the vinylester between granules at 5% (57 + 3 = 60, 3 / 60 = 0.05), for an overall cured density of 2.0 g/cc. Does this seem reasonable? The main problem I foresee is mixing the granules with the composite without accumulating piles of microparticles in front of them, which Alhuthali and Low point out creates focus points for mechanical stress (what they call "agglomerations" on p10).