Control strategy for angular gradations by means of the flow forming process

Control strategy for angular gradations by means of the flow forming process


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Abstract. Climate change, rare resources and industrial transformation processes lead to a rising demand of multi-complex lightweight forming parts, especially in aerospace and automotive sectors. In these industries, flow forming is often used to produce cylindrical forming parts by reducing the wall thickness of tubular semifinished parts, e.g. for the production of hydraulic cylinders or gear shafts. The complexity and functionality of flow forming workpieces could be significantly increased by locally graded microstructure and geometry structures. This enables customized complex hardness distributions at wear surfaces or magnetic QR codes for a unique, tamper-proof product identification. The production of those complex, 2D (axial and angular) graded forming parts currently depicts a great challenge for the process and requires new solutions and strategies. Hence, this paper proposes a novel control strategy that includes online measurements from an absolute encoder to determine the angular workpiece position. Workpieces of AISI 304L stainless steel with 2D-graded structures are successfully manufactured using this new strategy and analyzed regarding the possible accuracy and resolution of the gradation. At this point, a dependency of the gradations on the sensor and actuator dynamics, accuracy and geometry could be noted. It is further evaluated how the control strategy could be extended by an observer-based closed-loop property control approach to enhance the accuracy of the suggested strategy.

Flow Forming, Graded Structures, Control Strategy, Closed-Loop Property Control

Published online 4/19/2023, 12 pages
Copyright © 2023 by the author(s)
Published under license by Materials Research Forum LLC., Millersville PA, USA

Citation: KERSTING Lukas, ARIAN Bahman, ROZO VASQUEZ Julian, TRÄCHTLER Ansgar, HOMBERG Werner, WALTHER Frank, Control strategy for angular gradations by means of the flow forming process, Materials Research Proceedings, Vol. 28, pp 2049-2060, 2023


The article was published as article 220 of the book Material Forming

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