Numerical modelling of constrained groove pressing with deform 3d software
Dušan Kešner1, Petr Fišer1, Jaroslav Drnek1, Jozef Zrník1,2, Miroslav Cieslar3, Zbyšek Novy1
1Comtes FHT Ltd., Lobezská E987, 326 00 Plzeň, Czech Republic. 2University of West Bohemia, Univerzitní 22, 306 14 Plzeň, Czech Republic. 3Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, 121 16 Praha 2, Czech Republic.
DOI:
https://doi.org/10.7494/cmms.2007.1.0132
Abstract:
The Constrained Groove Pressing (CGP) is one of the many forming processes, which are used for preparation of ultrafine-grained structure in materials. With this technique, it is possible to manufacture bulk fine-grained products using a wide range of steels and alloys. The finite element method (FEM) modelling may be used for verification of design tool parameters, for optimization of the shape of the CGP-tools and for optimization of the forming process. It provides significant information on the effects of the tool geometry, material properties and friction upon the flow of material. In this study, numerical modelling has been used for investigation of forming with dies of different groove shapes, varying sample thickness and two different specimen materials (steel and aluminium alloy). The distribution and amount of effective strain and the magnitudes and changes in forming forces were evaluated. The calculation has shown the differences between the alternative forming configurations in terms of the distribution and amount of effective strain. The computation results were used as a basis for design of optimum-shaped tools and verifying the technological process. This optimum alternative has been experimentally tested. The plates prior to CGP had a coarse-grained recrystallized structure with large scatter in grain size. Specimens were forged with up to four strokes, each stroke introducing the strain of about 0.7 in the deformed segments. The impact of the experimental forming upon microstructure development was investigated with light microscopy, scanning electron and transmission electron microscopy of thin foils. The results show that the Constrained Groove Pressing with one completed pass resulted in formation of non-uniform finer microstructures with some new grains formed by intensive deformation and dynamic recrystallization process. The presence of low tensile and compressive strain in flat segments of specimens, resulted as well in grain refining process, as suggested by numerical simulation, has been confirmed by transmission electron microscopy observation. However, higher number of passes is required to further homogenize and refine the microstructure.
Cite as:
Kešner, D., Fišer, P., Drnek, J. Zrník, J., Cieslar, M., & Novy, Z., (2007). Numerical modelling of constrained groove pressing with deform 3d software. Computer Methods in Materials Science, 7(1), 130 – 135. https://doi.org/10.7494/cmms.2007.1.0132
Article (PDF):
Keywords:
Constrained Groove Pressing (CGP), Numerical simulation, Transmission electron microscopy, Light microscopy, Fine-grained microstructure
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