Hardness and Young's modulus behavior of Al composites reinforced by nanometric TiB2 elaborated by mechanosynthesis

Different milling conditions have been tried to produce nanoparticles of TiB2 to be used as reinforcement in Al matrix composite materials. The milling of TiB2 compounds leads to a decrease of both the crystallite size and the particle size. Moreover, we demonstrate that the use of optimized conditions with a vibratory miller allows – in a short period of time – the direct synthesis of nanoparticles of TiB2 starting from the elemental powders (Ti and B). Then TiB2 reinforced Al composite was fabricated using a simple powder metallurgy process followed by free sintering under controlled atmosphere. The influence of (i) the nanometric TiB2 particles grain size and (ii) their volume fraction on the hardness and Young's modulus, measured from nanoindentation tests, has been analyzed.