The department “Processing of functional materials” is focussing on exploring the combination of self-assembly and 3D printing processes to produce complex, hybrid, locally anisotropic materials. Specifically, the self-assembling structures are synthesized by means of dealloying methods such as liquid metal dealloying. The gained knowledge is transferred to the development of devices based on 3D hybrid materials with extraordinary physical and/or electrochemical properties and potential applications in energy generation and storage, lightweight construction, and medical technology.
Projects of Processing of functional materials
Hierarchical metal-metal composites mimicking elastic behavior of human bone
The close match between the elastic properties of a metallic implant and compact bone is crucial for avoiding the stress shielding effect. Therefore, low-modulus biomaterials are desirable for biomedical implants to promote rapid healing of hard tissue.
In this work, novel hierarchical (multi-stage) ZrTi-Mg metal-metal composites that ‘break’ the conventional correlation between strength and elastic modulus were synthesized using laser powder bed fusion (L-PBF) and liquid metal dealloying (LMD). The large artificial porosity (~300 μm) of the metallic scaffold was produced via L-PBF, while the fine porosity (~10 μm) resulted from the self-assembly of materials through LMD. The results demonstrate that the hierarchical architecture of artificial materials significantly influences their properties. The obtained average Young’s modulus is 4 GPa, which is an order of magnitude lower than that of bulk materials with similar composition (65 GPa) (Fig. 1). The first prototype of a biomedical distal radius locking plate has been successfully manufactured. These findings suggest that these novel composites, which mimic both the structure and mechanical behavior of bone, are promising candidates for biomedical applications.
Cooperation: Universität Bremen, International Collaboration Center, Institute for Materials Research (ICC-IMR), (Tohoku University, Sendai, Japan)
Funding: BMBF im Rahmen des LikeABone-Projekts 13XP5151
Contact:
M. Sc. Aleksandr Filimonov
Tel.: +49 421 218 51219
E-Mail: filimonov@iwt.uni-bremen.de
Determination of tracer molecules measured via mass spectroscopy
Overall goal of Pre-ignition Fire Detection System (PFDS) is to become aware of a fire before an ignition on the international space station ISS.
For reliable detection a neural network will be trained based on possible outgassings of materials found for various tasks on ISS. The volatile outgassings were determined for temperatures below known decomposition temperature and were found to be unique for each material. Tailor-made Substrate prototypes for a miniaturized-integrated sensor array were designed and checked by manufacturer for feasibility of production.
Cooperation: Institut für physikalische und theoretische Chemie, Eberhard Karls Universität Tübingen
Funding: DLR
Contact:
Malte Schalk
Tel.:+49 421 218 64516
E-Mail: m.schalk@iwt.uni-bremen.de
Simulation of structural changes of mesoporous films and layers during liquid infiltration and drying
Nanoparticles systems are characterised by hierarchical assemblies of sintered nanoparticles (5–50 nm) that in turn form sintered aggregates (200–300 nm) and further agglomerate to form extended nanoparticle assemblies called mesoporous films (1–50 μm).
The agglomeration mechanism is largely due to surface tension forces which dominate the dynamics at this scale. For example, restructuring occurs during liquid imbibition and drying of nanoparticle films. The aim of this project is to obtain a deeper theoretical understanding of surface tension forces at this scale. Therefore, new models and methods for fast and accurate computation of surface tension forces were developed.
Cooperation: Universität Bremen/FB04
Funding: DFG (GRK 1860)
Kontakt:
Stefan Christian Endres
Tel.:+49 421 218 51238
E-Mail: s.endres@iwt.uni-bremen.de