Synthesis of Porous TiAl-Mn Intermetallic Compounds by Reactive Sintering Process

Abstract

The porous Ti-45at.%Al-1.6at.%Mn intermetallic alloys were fabricated by reactive sintering process using warm extruded mixtures consisting of elemental titanium and aluminum alloy powders and subsequent heat treatment. At the extrusion stage, three different extrusion ratios were tried in order to provide the various types of porous structure in the microstructure. It was clearly found that the shape of pore and porosity are largely dependent on extrusion ratio. With increasing extrusion ratio the porosity decreased, on the other hand, aspect ratio of porous structure increased. The porosity measured was in the range from 35% to 45%. The maximum porosity of 45% can be obtained when the specimen was reactively sintered with the extrusion ratio of 1. A directionality of pores oriented parallel to the extrusion direction was found when the extrusion ratio of powder mixtures is 6 and above.