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).
Edited by TTK Ciar, 08 August 2015 - 1928 PM.