Highly porous rigid fibre structures made from light metals

Highly porous parts based on aluminium alloys are interesting materials for applications in thermal management and construction, whereas porous magnesium alloys are promising candidates for absorbable medical implants. Single short fibers of Al or Mg alloys with an equivalent diameter between 90 and 210 mu m were manufactured by melt extraction. Some fibers were coated before sintering to ensure good sinter contacts. Thermodynamic calculations were used to determine the alloy composition and the best conditions for liquid phase sintering for the selected alloys. The manufactured fiber structures show excellent sintering quality, good mechanical properties and high heat conductivity. Metallographic studies show good sintering contacts among the fibers as well as to housing sheets. Due to the rough surface of the fibers and the high porosity of the structures, they show a very high inner surface which is crucial for the targeted applications.