Cell Structure Control of Porous Titanium Composite Synthesized by Combustion Reaction

Abstract Porous titanium matrix composites were fabricated by a reaction between titanium powder and boron carbide (B₄C) powder. Precursors were made by compacting the elemental powder blend, and heated in an induction furnace to induce the reaction. The reaction was strongly exothermic and, therefore, it was a combustion mode when Ti/B₄C blending ratio of the precursor was appropriate. The reaction products were titanium boride (TiB or TiB₂) and titanium carbide (TiC). By controlling the Ti/B₄C blending ratio, it was possible to control the volume fraction of reaction products in the titanium matrix. The combustion synthesized material was porous and its cell structure was strongly affected by the processing condition of the precursor (porosity of the precursor and Ti/B₄C blending ratio). The open cell structure was made from precursors with low Ti/B₄C and high porosity. The cell size was varied from several tens of microns to about 500 microns by changing the combustion temperature.