Berlin 2024 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
MM: Fachverband Metall- und Materialphysik
MM 63: Functional Materials: Performance, Reliability and Degradation
MM 63.4: Vortrag
Donnerstag, 21. März 2024, 16:15–16:30, C 230
Thermomechanical properties of diamond abrasive grains — •Gabriel Brune1, Tountzer Dereli2, Lars Olschewski1, Monika Kipp2, Dirk Biermann2, and Jörg Debus1 — 1Department of Physics, TU Dortmund — 2Institute of Machining Technology, TU Dortmund
Abrasive grains are subjected to high thermomechanical stress during high-speed precision grinding. While cubic boron nitride is often used for its high hardness and thermal resistance, diamond - with its superior hardness - provides better grinding results. However, when machining steel at temperatures of about 600∘C, graphitization of the diamond surface is a major issue lowering the structural and chemical stability.
These structural and chemical changes including the influence of O2 and interfaces between sp2 and sp3 hybridized areas within the carbon network are in the focus of our studies. Accordingly, a series of diamond abrasive grains exposed to differently high thermomechanical loads was analyzed. Spatially resolved Raman spectroscopy of the diamond surface reveals the structural properties of the grains. Based on shifts of the diamond Raman peak at 1332 cm−1, tensile and compressive strain up to 200 MPa is determined. In particular, the observation of the D peak (around 1350 cm−1) and G peak (around 1550 cm−1) indicates the local formation of amorphous carbon clusters. From the peak shapes it is possible to estimate local maximum surface temperatures (= 660∘C) [APL Mater. 11, 031106 (2023)] that occured during the grinding process.
Keywords: Diamond; Raman Spectroscopy; Graphitisation; Abrasive Grains