Contact

Ivanova, Elvira M.Sc.
Head of Investment Casting
Chair for comprehensive Foundry Science and Foundry Institute

Tel.: +49 (0) 241 80 - 98152
e.ivanova@gi.rwth-aachen.de

Bionics

Besides the micro-structured surfaces dealt with in the Cluster of Excellence, the Foundry Institute pursues the research field of “structure-optimised foams” based on natural construction principles.

In an interdisciplinary research proposal “Design and manufacture of graded cellular endoprotheses and light-weight structures”, load-oriented, foam-like structures will be manufactured which are optimised with respect to their density distribution, macro and micro structures and their shape.

Mg-Ca-Zn as biodegradable implant material

The degradation of magnesium in aqueous electrolytes is used to generate implants which dissolve in-vivo within a specified time period. Different from non-resorbable implants, the subsequent surgical procedure in which the implant is removed is therefore eliminated. In addition to this, magnesium possesses similar physical and mechanical properties to those of human bone, it is an essential element of human metabolism and is correspondingly a very promising candidate for excellent biocompatibility and integrity. By purposefully designing an alloy using only non-toxic elements and selecting a suitable manufacturing process; and thereby a generated microstructure, specific degradation rates can be set.

Bionic - metallic foams

Cellular open-pored metallic structures represent a composite material having unique properties. Their low weight, good thermal conductivity, permeability and interpenetrability, their high porosity of up to 98 % and good energy absorption capacity establish these structures as extremely interesting for light-weight constructions. The energy damping properties, in particular, promise interesting applications as safety features for, for example, the automotive branch or the transport sector. The design of structures inspired by nature and manufactured using precision casting falls within the scope of the priority program SPP1420. In drop-tests, the cellular structure of the pomelo’s fruit-husk exhibits excellent energy dissipation during the fruit’s impact. As investigations show, evidence suggests that this property is derived from a particular hierarchical arrangement of the existing building-blocks. Here, the pomelo’s fruit-husk exhibits at least seven hierarchical levels. By rendering the individual hierarchical levels or combinations of hierarchies as engineered, open-pored metal foams; as composite materials possessing excellent energy damping, simultaneously promises low material input together with the associated light-weight properties.

Casting micro-structured surfaces

Another interesting field of bionics in casting technology is the rendering of bionic surface structures; such as the self-cleaning lotus leaf or the shark’s skin, onto engineering components such as the air restrictor developed at the Foundry Institute for racing competition.

Moreover, a project supported by the DFG is currently concerned with micro-structuring bioactive glasses using foundry technology. The objective of the interdisciplinary work is to directly obtain surface structures without post-processing which introduces energy that would induce undesirable recrystallization of the glass.