Effect of titanium diluent on the fabrication of Al2O3–ZrB2 composite by SHS dynamic compaction

An investigation on the effect of titanium as diluent (5–20 wt%) on the Al2O3–ZrB2 composite by self-propagating high temperature synthesis (SHS) dynamic compaction was carried out. Addition of titanium during the SHS synthesis could vary percentage of phases and microstructure. Small percentage addition (5 wt%) of titanium diluent helps in inhibition of grain growth of borides but further increase in diluent addition leads to formation of oxide phases and also titanium diboride. The vickers microhardness first increased with the addition of 5-wt% titanium and then decreased for further additions of titanium diluent up to 20 wt%. The maximum hardness was found as 2800 Hv0.025.