Nanoscale TiB2-dispersed Cu-matrix composite produced by a high-energy milling and self-propagating high-temperature synthesis process

Nanocomposite Cu-TiB₂ powder was in situ synthesized by means of self-propagating high-temperature synthesis (SHS) using high-energy ball milled Ti-B-Cu elemental mixtures as powder precursors. The effect of the preliminary mechanical treatment on the SHS reaction was studied. The size of TiB₂ particles produced by SHS was shown to decrease with increasing duration of the preliminary mechanical treatment. Subsequent mechanical treatment of the SHS products led to a reduction of TiB₂ particle sizes down to 30-50 nm. The microstructural evolution of the synthesized powder compacts during sintering was investigated. During spark plasma sintering a fine-grained skeleton of TiB₂ with well connected particles is formed. This interpenetrating phase composite of Cu-TiB₂ is produced by the simultaneous action of pressure, temperature and electrical current. TiB₂ nanoparticles distributed in the copper matrix agglomerate and form a fine-grained skeleton.