Processing and Pore Morphology Control of Porous Metals by Powder Processing Route

Abstract

ABSTRACT

Porous metals exhibit various unique physical and mechanical properties, such as low bulk density and high strain energy absorbing capability. The optimum shape of the pores (cell morphology and topology) depends on the required properties. In this paper, two processing methods (precursor method and reactive precursor method) and some attempts to control the cell structure are discussed. Porous aluminum alloys are fabricated by the precursor method. In this method, powder compacted precursor consisting of aluminum and titanium hydride powders are prepared. Upon heating the precursor, titanium hydride decomposes and releases hydrogen gas at around the melting point of aluminum. Then the hydrogen gas produces many pores in aluminum. As for the reactive precursor method, the precursors are made by blending at least two kinds of reactive elemental powders (e.g. aluminum and titanium powders). Closed, flat-disc, open, bimodal-sized and high-porosity open pores are currently achieved by the reactive precursor method.