Relationship between hardness and tensile tests in titanium reinforced with yttria nanoparticles

In situ Ti/Y2O3 nanocomposites have been developed and characterized, and the strengthening effects of the fine Y2O3 dispersion investigated. Samples, containing 0.3-0.7 wt.% of Y2O3 were prepared by arc melting technique. TEM analyses performed on as-cast and recrystallization annealed samples reveal the presence of a homogeneous dispersion of Y2O3 particles with sizes <100 nm. The mechanical properties have been determined by microhardness measurements and tensile tests. The hardness of the composites increases by a factor of 2 with respect to unalloyed Ti. Comparison between microhardness and tensile stress values follows the Tabor relationship. The validity of the relationship obtained between microhardness and tensile properties for nanocomposites is discussed.