Auslegung, Bau und Erprobung von #gamma#-TiAl Hohlschaufeln. Teilantrag B: Herstellung und Kompaktieren von #gamma#-TAB Pulvern sowie Optimierung der 'Diffusion Bonding' Technik fuer diese Legierung Abschliessender Sachbericht

With respect to weight reductions for aeroengines, in this project a process route for hollow turbine blades has been developed and a respective hollow blade has been manufactured using the #gamma#-TiAl-alloy '#gamma#-TAB'. The weight of a hollow blade is reduced to about 60% with respect to a massive TiAl-blade. The weight of a massive TiAl-blade is about 50% compared to a massive nickel based one. The process route developed involved the following steps: (1) Alloy power production by gas atomization, (2) compaction of the powders by HIP to rectangular slabs suitable for rolling, (3) rolling of TiAl-sheets, (4) diffusion bonding of sheets, (5) superplastic forming of the hollow structure. In this part of the project the process steps (1), (2) and (4) have been developed. The most important results are: 1. Using a novel gas atomization facility, pure and chemical homogeneous alloy powders with a high fraction of unde size particles have been produced. 2. By hot isostatic pressing slabs characterized by a fine grained microstructure and a high degree of chemical homogeneity were obtained. 3. Process parameters as surface quality, pressure, temperature and time have been optimized such that sound bonds were obtained using industrial diffusion bonding equipment designed for conventional Ti-alloys. (orig.)SIGLEAvailable from TIB Hannover: F00B558+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung und Forschung (BMBF), Bonn (Germany)DEGerman