Self-propagating foaming process of Al-Ti reactive precursor for fabricating long scale porous materials

The authors have been investigating a novel processing route in which foam materials are made by self-propagation process. This fabrication process uses chemical reactions so called "Self-propagating high-temperature synthesis (SHS)", which releases high heat of reaction. To make a foamable precursor, titanium and aluminum powders are blended by Al/Ti molar blending ratio of 4.0. An exothermic agent (boron carbide, B4C) powder, which releases high heat of reaction and increases the combustion temperature, was added to promote the foaming behavior. The powder blend was hot extruded and rolled to make long scale precursors. The thickness of the precursor was varied from 1mm to 4mm. The precursors were heated by both volume combustion synthesis and self-propagating high-temperature synthesis modes. In this presentation, we focus on the self-propagating and foaming behaviors of long scale Al-Ti precursors..