Jäckisch M, Merklein M (2020)
Publication Language: English
Publication Type: Journal article
Publication year: 2020
Book Volume: 50
Pages Range: 220-225
URI: https://www.sciencedirect.com/science/article/pii/S235197892031739X
DOI: 10.1016/j.promfg.2020.08.041
Open Access Link: https://www.sciencedirect.com/science/article/pii/S235197892031739X
Minimizing tool wear is a crucial goal in metal forming to increase the tool durability and thus reduce costs. One approach is to superimpose the tool movement with a high frequency oscillation. The so-called ultrasonic assistance enables an immediate process force reduction and lowers the workpiece and tool loads significantly. This phenomenon has been discovered by Langenecker and Blaha in 1955 and since then been confirmed for several forming applications like wire drawing, deep drawing and forging. Nevertheless, the underlying softening mechanisms are still subject of current research. Explaining theories may be attributed to the principle of stress superposition, surface and volume effects. The latter includes the thermal softening due to ultrasonic vibration. Moreover, interactions as well as the proportional force reduction of these effects vary with the process parameters and the investigated material. Therefore, this paper aims for the separation and quantification of thermal softening with respect to the process parameters. Ultrasonic-assisted compression testing with the steel C35E is carried out with an oscillation frequency of 20 kHz. Process forces as well as specimen heating are measured with regard to the tested amplitudes and deformation rates. Based on these measurements, hot compression tests are conducted with identical temperature slopes. This way, thermal softening is determined and can be separated from acoustic softening effects. Besides, material hardening is determined for ultrasonic-assisted and temperature controlled compression. Using a shortened oscillation interval the influence of both, the superimposed oscillations as well as the specimen heating is proven.
APA:
Jäckisch, M., & Merklein, M. (2020). Investigation of thermal effects during ultrasonic-assisted upsetting. Procedia Manufacturing, 50, 220-225. https://dx.doi.org/10.1016/j.promfg.2020.08.041
MLA:
Jäckisch, Manuel, and Marion Merklein. "Investigation of thermal effects during ultrasonic-assisted upsetting." Procedia Manufacturing 50 (2020): 220-225.
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