Wear-Resistance in Natural Materials: The Role of Micro-Architecture

• Applicant: Dr. Maryam Tadayon
• Subject Area: Biomaterials
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 490987316

All mechanically working elements are exposed to wear damages, and biological tools are no exception. Through diverse, sophisticated hierarchical architectures, natural load-bearing materials exhibit outstanding tribological performance, essential to the survival of the species. Dental structures, for instance, are required to tolerate repetitive contact loads without significant loss of material. However, very little is known about wear damage mechanisms, and a single inclusive analytical model does not exist in order to predict them. In this proposed research, we will combine different state-of-the-art experimental techniques and numerical studies to identify the wear damage mechanisms of heterogeneous biological model systems namely, the arthropod cuticular tools (chitin-based) and crayfish mandible (apatite/chitin-based), considering their specific function within the biological system. We will use diverse methodologies to characterize these model systems in terms of material composition, micro-architecture, and micro-mechanics. Moreover, following the induction of multi-directional damage, comprehensive post-damage monitoring will be performed in order to correlate the mechanical failures to the inherent material micro-architecture and thereby, to elucidate the dominant wear and crack-dissipation mechanisms. The stress field geometry will be predicted by numerical finite element studies to further understand the role of micro-architecture anisotropy, mechanical gradation, and tribological properties. Gaining insight into the wear damage mechanisms and material heterogeneity may thus serve to elaborate on established contact mechanics theory regarding yield and crack failure stresses and introduce new valid parameters into the wear damage assessment framework. Our comprehensive experimental work can also serve to develop novel design principles for the fabrication of high-performance, wear-resistant, bioinspired functionally graded materials and coatings for industrial and biomedical applications.

• DFG Programme: Research Grants