The 9th International Conference on Multiscale Materials Modeling

講演情報

Symposium

O. Tribology and Interface: Multi-Scale, Multi-Physics, and Multi-Chemistry Phenomena in Friction, Lubrication, Wear, and Adhesion

[SY-O1] Symposium O-1

2018年10月29日(月) 13:30 〜 15:15 Room5

Chairs: Lars Pastewka(University of Freiburg, Germany), Izabela Szlufarska(University of Wisconsin, United States of America)

[SY-O1] A novel multiscale framework for modeling of diamond tools wearA novel multiscale framework for modeling of diamond tools wear

Adriana Quacquarelli1, Nicolas Fillot1, Guilhem Mollon1, Thierry Commeau2, Aurelie Nouveau2 (1.Université de Lyon, LaMCoS, INSA-Lyon, CNRS UMR5259, F-69621, France, 2.Umicore Specialty Powders France, France)

Stone cutting involves diamond impregnated tools (DIT) consisting in microdiamonds embedded into a metallic binder. Diamond Tools lifetime is influenced by the wear mechanism of the metallic matrix due to the abrasive debris flow generated during cutting process. Both diamonds, stone debris and the metallic matrix have different dimensions. Therefore, different mechanical and physical process, somehow related, are involved at different scales. Experimental tests are necessary but not sufficient to predict the overall behaviour of diamond tools. A numerical multiscale approach is then initiated to extend the experimental approach.

As DIT performance is influenced by the microstructure properties of the binders (porosity, grains size, bulk properties and composition of metallic powder), a microscopic 2D model representative of metal microstructure has been built. A multibody meshfree technique coupled with a Discrete Element Method (DEM) approach is used. The granular swarf is described by rigid grains with realistic shape, while the metallic matrix is represented by a collection of degradable grains which fails by fatigue due to the continuous generation and flow of rock debris. Cracking initialization and propagation can be monitored. In typical sections far from diamond, an empirical local wear law can be written, proposed and compared to experiments.

At another scale, the flow of stone debris is studied and assimilated to a viscous flow of continuous material.

Then, A 3D continuous model is implemented to monitor wear close to diamond. The pressure field is obtained by solving Reynolds equation and used in a global wear law. The microgeometry evolution is then compared to experiments.

Finally, the whole set of numerical models at the different scale can be used as a tool to anticipate the performance of the metallic matrix of diamond tools.