Investigation of the sintering kinetics of gas-borne nanoparticles on short time scales

• Applicant: Dr.-Ing. Franz Huber
• Subject Area: Mechanical Process Engineering ; Technical Thermodynamics
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 565977284

The aim of this project is to develop a measurement method and provide time-resolved data on the sintering kinetics of gas-supported fractal nanoparticle aggregates at high temperatures. Sintering kinetics play a major role in many processes and process steps involving particles, for example in particle formation or in targeted material processing by laser sintering. Although sintering models are available in the literature, the material data required for their application is often not fully available. So far, there is a lack of experimental possibilities to directly determine time scales for different sintering processes at high temperatures. In this project, metallic particle aggregates are used to investigate the sintering kinetics. These are produced in a spark generator and then heated strongly within a short time by absorbing a short laser pulse (ns and ps laser). Depending on the laser energy, different temperatures of the particles are reached, which in turn leads to different sintering mechanisms. These have different characteristic time scales from a few 100 ps to a few 100 ns. In this project, the kinetics are investigated by time-resolved determination of the aggregate size at different times after laser irradiation using short-pulse lasers (ns and ps). Laser-based wide-angle light scattering (WALS, for aggregate size) and two-color-pyrometry (2CP, for temperature) are used for this purpose. Time-resolved measurements of the sintering kinetics at different heating laser energies on different particle materials allow the provision of experimental data on sintering kinetics at high temperatures and thus on ultra-short time scales. These data are highly relevant, for example, for the improvement of processes / the development of new processes for the synthesis of nanoparticles or for the (further) development of laser-based measurement techniques for nanoparticles. Furthermore, the results obtained on fast sintering kinetics can be used for the first time to validate and improve corresponding sintering models at high temperatures.

• DFG Programme: Research Grants