Analysis of wear phenomena during forward extrusion under dry friction conditions
| Autor: | Patrick-Marcel Mattfeld, Tobias Brögelmann, Rafael Hild, D.C. Hoffmann, Nathan Kruppe, Fritz Klocke, Thomas Bergs, Daniel Trauth, Kirsten Bobzin |
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| Rok vydání: | 2019 |
| Předmět: |
Work (thermodynamics)
Materials science Dry friction Metallurgy 02 engineering and technology Surfaces and Interfaces Tribology 021001 nanoscience & nanotechnology Condensed Matter Physics computer.software_genre Forging Surfaces Coatings and Films Simulation software 020303 mechanical engineering & transports 0203 mechanical engineering Mechanics of Materials Materials Chemistry Extrusion 0210 nano-technology computer |
| Zdroj: | Wear. :1362-1370 |
| ISSN: | 0043-1648 |
| Popis: | Tools in cold forging processes experience high loads. In order to reduce the process loads, solid and liquid lubricants are used. The use of lubricants is disadvantageous due to ecological, economical, and legislative reasons. Novel approaches in cold forging aim at the use of ecologically benign lubricants or avoiding the usage of lubricants completely. This paper focuses on the substitution of lubricants in cold forging by surface textures on workpieces and self-lubricating coatings on tools. The potential of surface textures on workpieces and self-lubricating tool coatings to reduce friction and wear in dry forging was demonstrated in preliminary work using analogy experiments. After analogy tests under dry tribological boundary conditions have shown positive results in preliminary work, dry full forward extrusion tests were performed in this work. Firstly, the focus of the investigations was on feasibility. Secondly, the potentially best combination with regard to friction and wear reduction was selected. Thirdly, in addition to force profiles, the surface of cold forging dies was studied by means of SEM. At the same time, the processes were supported by a validated numerical FE process simulations with the simulation software Forge NxT 2.1. The dry full forward extrusion experiments were successful, because the specimens were extruded until the final point and could be ejected without failure. It was observed that the highest wear of the dies occurred not in the region with the highest tool load but in the region with relatively low loads. Furthermore, it was shown that no wear model suitable for cold forging exists so far. |
| Databáze: | OpenAIRE |
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