Papers by Author: Carolin Körner

Abstract: Titanium aluminides are highly attractive for high temperature applications involving dynamic components, e.g. turbine blades or turbocharger wheels, due to their high strength-to-weight ratio. The drawback is the difficult manufacturing of this material class due to the low toughness and high sensitivity to oxygen. Selective electron beam melting SEBM shows a new approach of producing complex titanium aluminide parts without a major oxygen pick up and avoiding problems with brittleness. The high cooling rates of this process lead to a very fine microstructure, which is not fully understood up to now. The microstructure determines the creep properties and therefore defines the performance of this material in high temperature applications. In this contribution, the creep properties of Ti-48Al-2Cr-2Nb fabricated by SEBM are investigated. The influence of the processing parameters and the building direction on the microstructure and the creep properties are discussed and compared to cast material.

Abstract: The complete integration of piezoceramic sensor/actuator-modules into metal components using high pressure die casting is a promising approach for the fabrication of multifunctional structural elements with enhanced properties. A technique providing stabilization and protection of the module during the highly dynamic mould filling is presented. Demonstration parts are produced which are fully capable to detect vibrations. An approach to characterize this sensory functionality of the adaptronic system is presented.

Abstract: Integral foam molding (IFM) is an economical near net-shape technology to produce monolithic castings with solid skin, foamed core and continuous density transition between skin and core. It was developed for polymers in the 1960s. But it took about ten years to optimize the molding technique and the quality of the polymer integral foam parts to a marketable stage. Meanwhile, polymer integral foam parts are established in a lot of commercial applications. The situation is completely different for metals. The first attempts to produce metal integral foam parts were made only a few years ago. A cost effective injection molding technique for magnesium integral foam was developed at the WTM-Institute in Erlangen, Germany. The low-cost production in combination with the integral foam properties low density, high weight specific bending stiffness and remarkable damping capacity is very promising. At the beginning we produced only parts with simple shape, for example plates. But if we think about commercial applications, more complex parts with a three-dimensional shape are required. The focus of this paper is on new developments concerning the production of magnesium integral foam parts with complex shape like a casing cover or a door handle.