Fundamental characterization and analysis of the lubricating effect of quasicrystalline powders as an intermediate medium in the chip formation zone

• Applicant: Professor Dr.-Ing. Dirk Biermann
• Subject Area: Metal-Cutting and Abrasive Manufacturing Engineering
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 533723637

The use of cooling lubricants is associated with a high expenditure of energy as well as high costs. On the other hand, the effectiveness of the media used is limited, especially with regard to lubrication. Major causes of this are the high contact normal stresses and temperatures in the chip formation zone. This gives rise to the need to research and develop further lubricants that permit a more efficient and thus energy- and resource-saving use. Quasicrystals offer a promising approach here, as they have exceptional tribological properties that are mainly expressed in low frictional resistance. Due to the high mechanical stability of quasicrystals, these properties can also be expected at high pressures and have been demonstrated by other scientists over a very wide temperature range. In the course of own preliminary investigations, it was shown that quasicrystal powder mixed with a conventional cooling lubricant emulsion can significantly reduce frictional resistance in the chip formation zone. Furthermore, it turned out that repeated contact of the tool with the quasicrystals significantly reduced the mechanical stresses even in a subsequent dry machining operation. The aim of the present project is to explore the mechanisms of action of the identified effects and thus to create a basis for the development of quasicrystal-based lubricants for metal-cutting production. For this purpose, the interaction with various liquid cooling lubricants and the influence of different grain sizes of the quasicrystal powders on the lubricating effect will first be investigated in fundamental orthogonal cutting investigations. In a next step, it is planned to investigate the suitability of the quasicrystals as an additive for minimum quantity lubrication oils. In addition to the resulting lubricating effect compared to liquids without solid particles, the experiments will also focus on possible challenges in the atomization of the media. At the end of the proposed project, turning experiments on the influence of the friction reduction by quasicrystals on the wear evolution of the tools are to be conducted. Since the wear progress is strongly temperature-dependent, the temperatures on the rake face of the tool are to be measured with the aid of an innovative test rig. In comparison with dry machining and cooling lubrication with conventional media, these will serve as a further measured variable in order to be able to evaluate the lubrication effect of the quasicrystals.

• DFG Programme: Research Grants