A Method for Determining the Workability Diagram by Varying Friction Conditions in the Upsetting of a Cylinder between Flat Dies
Abstract
:1. Introduction
2. Theoretical Basis
3. Design of Experiment
4. Experimental Results
5. Workability Diagram
6. Conclusions
- Compared to other methods, the new method requires specimens of very simple shape (circular cylinders) and very simple dies (flat dies);
- Neither experimental nor numerical determination of stress components is required at the site of ductile fracture initiation;
- The friction law’s formulation is not required, though the friction stress is the agent for varying the state of stress and strain at the site of ductile fracture initiation;
- It has been confirmed by comparing the workability diagrams available from the literature and determined in the present paper that the new method is reliable (Figure 6);
- The new method covers the range of the average stress triaxiality between −1 to 0, approximately (Figure 6). It can be combined with specimens of various geometric shapes to extend this range. This will be the subject of a subsequent investigation.
Author Contributions
Funding
Conflicts of Interest
References
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Series | Initial Geometry | Geometric Parameters | Tribological Conditions | |
---|---|---|---|---|
Lubrication | Surface | |||
1 | | d0 = 20 mm h0 = 24 mm z0 = 4 mm | Mineral oil | Turned |
2 | Mineral oil | Ground | ||
3 | Teflon (polytetrafluoroethylene PTFE) | Turned | ||
4 | No lubrication | Turned | ||
5 | d0 = 20 mm h0 = 26 mm u = 0.6 mm t = 0.3 mm z0 = 4 mm | Stearin | Turned |
Chemical Element | C | Si | Mn | P | S | Cr | Mo | Ni | Cu |
---|---|---|---|---|---|---|---|---|---|
Content (%) | 0.46 | 0.23 | 0.64 | 0.008 | 0.022 | 0.18 | 0.02 | 0.08 | 0.17 |
Series | 1 | 2 | 3 | 4 | 5 |
---|---|---|---|---|---|
0.82 | 0.752 | 0.961 | 0.725 | 0.92 | |
−1.082 | −0.867 | −1.426 | −0.735 | −1.74 |
Series | 1 | 2 | 3 | 4 | 5 |
---|---|---|---|---|---|
A | −0.5127 | −0.3476 | −0.3661 | −0.6188 | −0.4505 |
B | 0.257 | 0.5589 | 0.2006 | 0.5612 | 0.0386 |
Series | 1 | 2 | 3 | 4 | 5 |
---|---|---|---|---|---|
1.15 | 0.95 | 1.47 | 0.85 | 1.74 |
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Movrin, D.; Milutinovic, M.; Vilotic, M.; Alexandrov, S.; Lang, L. A Method for Determining the Workability Diagram by Varying Friction Conditions in the Upsetting of a Cylinder between Flat Dies. Crystals 2021, 11, 1411. https://0-doi-org.brum.beds.ac.uk/10.3390/cryst11111411
Movrin D, Milutinovic M, Vilotic M, Alexandrov S, Lang L. A Method for Determining the Workability Diagram by Varying Friction Conditions in the Upsetting of a Cylinder between Flat Dies. Crystals. 2021; 11(11):1411. https://0-doi-org.brum.beds.ac.uk/10.3390/cryst11111411
Chicago/Turabian StyleMovrin, Dejan, Mladomir Milutinovic, Marko Vilotic, Sergei Alexandrov, and Lihui Lang. 2021. "A Method for Determining the Workability Diagram by Varying Friction Conditions in the Upsetting of a Cylinder between Flat Dies" Crystals 11, no. 11: 1411. https://0-doi-org.brum.beds.ac.uk/10.3390/cryst11111411