Project Details
Projekt
Modelling and synthesis of adsorption and reaction layers
Subject Area
Synthesis and Properties of Functional Materials
Term
since 2026
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 556252784
The scope of the project to explore the phase evolution and the properties of reaction layers on machine elements as a function of chemical composition by a combined theoretical/experimental approach of two sub-projects using quantum-mechanical simulations as well as characterization of (synthetic) reaction and adsorption layers. In the first sub-project (AP 1-3) the adsorption energy of selected ZDDP decomposition products on synthesized model reaction layers will be calculated using density functional theory (DFT). Moreover, the temperature dependence of the local binding of ZDDP adsorption products will be assessed using ab initio molecular dynamics (AIMD) on the target for a theoretical description of the interface formation/evolution on an atomistic level. Additionally, ZDDP adsorption layers will be synthesized using physical vapor deposition (PVD) in high vacuum and characterized for chemical adsorbate-substrate interaction and area coverage using X-ray photoelectron spectroscopy (XPS) for validation. The second sub-project (AP 4-6) seeks to understand the experimentally observed phase formation in the reaction layer as a function of chemical composition by comparison of the reaction layer formation energies. The pressure and temperature dependence of the phase formation will be considered by determination of elastic constants using DFT simulations as well as lattice dynamics calculations. Data generated by high-resolution characterization of real interfaces (TP6, TP7) will be continuously implemented to improve the simulation models. Additionally, model reaction layers will be synthesized using PVD and characterized rearding their elastic properties (nanoindetation), chemical binding states (XPS), and structure (electron backscatter diffraction, EBSD) as well as local chemical composition on the nanometer scale by atom probe tomography (APT). The thermal conductivity of the moedel reaction layers will be determined externally by time-resolved thermoreflectance (TDTR) and calculated with ab initio lattice dynamics approaches. Through combinatorial synthesis and characterization of the composition-dependent elastic properties and thermal conductivity we aim at identifying an improved reaction layer for real applications. Simulation (IAC) and experiment (MCh) will be employed iteratively: The material selection for the combinatorial synthesis is guided by quantum mechanics whereas the simulationmodel will be refined on the basis of characterization data obtained on synthesized thin films.
DFG Programme
Research Units
