Papers by Author: Olaf Andersen

Abstract: The present study addresses the need for grain refinement in free sintered titanium alloys produced by 3D screen printing. Thermohydrogen processing (THP) was used for temporary alloying Ti-6Al-4V with hydrogen to refine its microstructure. The impact on microstructure was investigated by a parameter study with varying temperatures, exposure times and hydrogen partial pressures. Heat treated specimens were examined by optical microscopy, XRD and thermal analysis. The influence of the refined microstructure on the mechanical properties was evaluated by tensile and microhardness testing. Ultrafine grained microstructures with ultimate tensile strengths of up to more than 1000 MPa could be produced.

Abstract: Sintered metal fiber structures show a favourable ratio between pressure drop and inner surface area. Their exclusively open-cell morphology makes them well suited for heat transfer or temporary heat storage applications. Recently, highly conductive sintered metal fiber structures were successfully prepared from melt extracted aluminum alloy fibers. The heat conduction and fluid flow properties of metallic sintered short fiber structures were determined experimentally and compared with simple analytical models. It was found that equations taken from the available literature yield good approximations to the experimental results.

Abstract: inno.zellmet is a large funded project which aims at the commercialisation of new, non-foam types of cellular metals. The project focuses on porous structures made from metallic short fibers and structures made from metallic hollow spheres, which are both chararacterised by multifunctionality and low specific weight. Six research institutes and 17 partners from industry constitute a local network that jointly develops solutions based on these "constructed materials". Target applications are situated in industrial sectors such as light-weight construction, decentralised energy generation, medical and biotechnology, as well as sound absorption and explosion protection for stationary machinery. inno.zellmet has started in March 2005 and will run for 3 years. During this time, it receives 3.9 Mio. EUR in funding from the German Federal Ministry of Education and Research under the "Unternehmen Region" initiative. This paper highlights some of the results obtained so far.