Effects of calcium nitride and calcium carbonate gasifying agents on the porosity of Ni₃Ti–TiC composites produced by combustion synthesis

Combustion synthesis or Self-propagating High Temperature Synthesis (SHS) has been used to produce highly porous materials intended for biomedical applications. Two novel gasifying agents, calcium nitride and calcium carbonate, were employed to increase product porosity and pore size during the combustion synthesis reaction for two SHS chemical compositions. A greater increase in apparent porosity of the products was gained using calcium carbonate compared with calcium nitride. Conversely, a greater increase in the number of pores falling within a 101–500 μm range was gained using calcium nitride compared with calcium carbonate. A greater increase in product porosity and pore sizes was observed for the TiC-50 wt% Ni₃Ti than the TiC-30 wt% Ni₃Ti with both gasifying agents.