13th International Conference on the Technology of Plasticity (ICTP 2021): Agile MF I
Program Organizers: Glenn Daehn, Ohio State University; Libby Culley, The Ohio State University; Anupam Vivek, Ohio State University; Jian Cao, Northwestern University; Brad Kinsey, University of New Hampshire; Erman Tekkaya, TU Dortmund; Yoshinori Yoshida, Gifu University
Monday 9:15 AM
July 26, 2021
Room: Virtual: Room C
Location: Virtual
Session Chair: Gerhard Hirt, RWTH Aachen University
Roll Forming of Cup with Curved Rotary Profile: Baohong Zhang1; Bin Hu1; Chunyu Wei1; Xi Zhao1; 1North University of China
In order to improve the production efficiency and material utilization of cup with curved rotary profile, a new method of roll forming is proposed. That is, a roll forming equipment with a set of preforming rolls and a set of shaping rolls is mounted on the drawing hydraulic press to form curved rotary profile of cup. Influence of roller number on the roll forming was studied by numerical simulation. The results show that the mouth of the workpiece is extremely uneven after performing with two-rolls, and part of metal flows into the gap of rolls, which forms a thin flash edge and folds during shaping. The mouth of the workpiece is relatively even after preforming with three-rolls or four-rolls, and folding is not found after shaping. The accuracy of numerical simulation is verified by the experiment, cups with curved rotary profile that meet the requirements were formed.
Flexible Manufacturing of Concave-convex Parts by Incremental Sheet Forming with Active Medium: Sebastian Thiery1; Noomane Ben Khalifa1; 1Leuphana University of Lüneburg
Incremental sheet forming with active medium (IFAM) is a flexible manufacturing process that creates concave-convex sheet metal parts in one clamping without needing a counter tool or a die. In the first study of this new process [1], a conventional hemispherical tool has been used in interaction with pressurised air to manufacture concave-convex parts. Thereby the geometric accuracy was not satisfying, so that within the present study, a conical tool with dedicated angle is introduced to IFAM. The idea behind this tool concept is to restrict the inclined part wall to a target angle. At first, results from numerical investigation show an improvement of the accuracy when a conical tool is used to manufacture a truncated convex pyramid. Subsequently, experiments validate the numerical model and reveal an increased process reliability. Experimental investigations of truncated convex cones and concave-convex parts close the paper and underline the feasibility of the tool concept.
Manufacturing of Tailored Blanks with Pre-shaped Involute Gearings by Using a Flexible Rolling Process and Its Application in a Sheet-bulk Metal Forming Process: Manfred Vogel1; Robert Schulte1; Onur Kaya1; Marion Merklein1; 1Institute of Manufacturing Technology
Nowadays, the efficient production of complex functional components in short process chains is important due to the goal of a further reduction of greenhouse gases. Therefore, the new process class of sheet-bulk-metal forming was developed, which combines the advantages of sheet- and bulk forming operations. One approach is the application of a flexible rolling process for manufacturing tailored blanks to improve the components properties.Heretofore, only geometries with a homogenous local material thickening were manufactured, to ensure a proper die filling of functional elements. In order to increase the intricacy, a new design that contains involute gearing cavities is introduced. In this paper the mild deep drawing steel DC04 with an initial sheet thickness of t0 = 2.0 mm is used to present new manufacturing approaches. Furthermore, the subsequent application of the tailored blanks in a calibration process is shown, with a characterization of the geometrical and mechanical properties.
The Dieless Drawing Process for the Elongation of Ultrafine Copper and Brass Wire: Andrij Milenin1; Piotr Kustra1; Mirosław Wróbel1; Marek Packo1; Valeriy Pidvysots'kyy2; 1AGH University of Science and Technology; 2Institute for Ferrous Metallurgy
In the study a new process for the production of ultrafine copper and brass wires is proposes. The proposed process is based on the dieless drawing. The workpeace for dieless drawing is a thin wire (100 microns) obtained by a conventional drawing method. The proposed technology is based on the implementation of a multi-pass incremental deformation. Moreover, in each pass, strain and strain rate sensitivity of flow stress should be positive and significant. The deformation parameters in each pass are determined on the basis of an analysis of the dependence of the flow stress on the strain, strain rate and temperature. For this purpose, plastometric tests of copper and CuZn37 alloy were performed. For estimation of technological plasticity and wire surface roughness physical and numerical modeling of dieless drawing were performed. The obtained data were used in the practical implementation of the incremental dieless drawing technology.
Deformation Analysis in Ultrasonic-assisted Multi-stage Incremental Sheet Forming: Zinan Cheng1; Yanle Li1; Fangyi Li1; Jianfeng Li1; 1Shandong University
Multi-stage incremental sheet forming (MISF) is a novel manufacturing process in which complex 3D shapes can be formed through a series of forming processes using generic forming tools. This study aims to explore effects of ultrasonic vibration on the MISF process and reveal the deformation mechanism based on the microstructure analysis. First, the initial, intermediate and final shapes were designed for the MISF in which the wall angle and depth deviation of the adjacent stage should be decreased. Then, a series of experiments for ultrasonic-assisted ISF was performed during which the strain evolution was recorded by the digital image correlation system. Furthermore, the microstructure evolution (e.g. grain size, misorientation and texture) of the formed parts under different forming conditions and forming stages was examined through the optical microscope (OM) and the electron back-scatter diffraction (EBSD). Through this study, further insight into the deformation mechanism during the ultrasonic-assisted MISF was provided.
Robotic Roller Forming Process and Strategies to Eliminate Geometrical Defect of Edge Waves: Yi Liu1; Junying Min1; Jianping Lin1; 1Tongji University
Robot-based roller forming (RRF) is a new dieless and flexible forming process using a roller mounted on an industrial robot to form sheet metal products by a number of passes with predefined tool paths. In this study, DP590 (dual-phase) steel sheets were initially formed to bent specimens having a right angle by RRF with 3 passes, and edge wave defects were observed at the flange of the DP590 specimens. Finite element analysis was utilized to reproduce the edge waves. According to finite element simulation, longitudinal plastic strains are generated at the flange edges due to excessive tensile and compressive stresses, which results in severe edge waves. Two strategies are introduced to reduce edge waves. One is to optimize forming parameters, and the effects of forming angle increment and moving direction of the roller on longitudinal peak strains at the flange edges were evaluated. Another strategy to reduce edge waves is to apply laser heating in RRF, where the heating spot is always in front of the roller. Experiments demonstrate that laser heating reduces forming forces and edge waves with fewer forming passes.
Open-die Forging of Copper Cone: Amnon Shirizly1; Gilad Harpaz1; Avner Shmuel1; 1Rafael
The open-die forging/upsetting of bulk material to cone shape involves high plastic deformation. The plastic strain caused major changes in the mechanical and metallurgical characteristics. Aim to gain better understanding of those characteristics change, experimental plane followed by analytical and numerical models were developed and established. The material properties and the friction condition (with several lubricants) were measured prior the process modeling. A analytical models (upper bound and Lower bound) were simulate the forging forces and compere to finite element model. The models support and compere to the experimental work using C101 copper. The preform samples were surface etched by grid pattern and strain caused by the Forming Operations measured due the grid changes, while, the flow pattern inspected and compered using a resemble material and numerical model. Good comparison were found between experimental results and the theoretical models.
Penetrating Tool Friction Stir Incremental Forming Using Alternating Tool Path Direction: Wei Jiang1; Takuya Miura1; Ryo Matsumoto2; Masato Okada1; Masaaki Otsu1; 1University of Fukui; 2Osaka University
In order to improve limit of forming height in penetrating tool friction stir incremental forming, alternating tool path direction was proposed. In this method, a forming tool was rotated at a clockwise direction and tool was moved along a tool path in a clockwise direction and counter-clockwise direction, alternatively. Pure aluminum sheets which size is 200 mm x 200 mm x 2 mm were formed into a truncated conical shape. Forming limit in height and distributions of volume change obtained in alternating tool path direction and solo tool path direction were compared. Repeatability, formable working conditions and forming accuracy were also investigated. From the results, forming limit in height was dramatically improved than that by the conventional tool path. The forming accuracy of the formed parts by penetrating tool friction stir incremental with the proposed tool path was better than that by the conventional single point incremental forming.