Effect of neutron irradiation on non-equilibrium HfB₂-B₄C composites

We studied the effect of neutron irradiation on composite material HfC-HfB₂- C made using rapid reactive hot pressing technology. The histograms of microhardness and results of X-ray phase analysis, obtained both before and after neutron and electron irradiation of the samples, were considered. It was found that secondary electrons make a considerable contribution at low-fluence (~10¹⁴ neutron/cm² ) neutron irradiation. Afluence range was determined at which reduction of composite material microhardness is observed

Modification of sintered iron properties by Y₂O₃ nanoparticles

Influence of Y₂O₃ nanoparticles on sintered iron structure and microhardness is investigated. Ferrite grain growth is shown to be slowed down by the clusters which cause altering the grain shape from needle-like to equiaxial (with lower specific surface). Yttrium oxide particles resulted microhardness increasing to 3.6 GPa at 1 % of second phase content. The fact is explained by retardation of dislocations on disperse particles by the Orowan mechanism