scholarly journals Cold forging of a hollow flanged part by an unconventional extrusion method

2021 ◽  
Vol 2130 (1) ◽  
pp. 012019
Author(s):  
G Winiarski ◽  
T Bulzak ◽  
Ł Wójcik ◽  
M Szala

Abstract This paper presents a numerical analysis of a new cold forming process for a hollow part with an external flange. The following techniques were used: forward extrusion, an unconventional method of extrusion with a moving sleeve, and upsetting in a tapered die cavity. The billet (42CrMo4 steel tube) was formed at ambient temperature. The study aimed to investigate the proposed method in terms of forged part accuracy. The following are examined and discussed: material flow, process force parameters in relation to tool strength, energy consumption of individual operations, as well as the distributions of strains, stresses, temperature and Cockcroft-Latham integrals in the produced part. The study has confirmed that hollow forged parts with external flanges of relatively large diameters and heights can be cold formed in several operations using different techniques.

2021 ◽  
Vol 2 (3) ◽  

Cold forging is a high-speed forming technique used to shape metals at near room temperature. and it allows high-rate production of high strength metal-based products in a consistent and cost-effective manner. However, cold forming processes are characterized by complex material deformation dynamics which makes product quality control difficult to achieve. There is no well defined mathematical model that governs the interactions between a cold forming process, material properties, and final product quality. The goal of this work is to provide a review for the state of research in the field of using acoustic emission (AE) technology in monitoring cold forging process. The integration of AE with machine learning (ML) algorithms to monitor the quality is also reviewed and discussed. It is realized that this promising technology didn’t receive the deserving attention for its implementation in cold forging and that more work is needed.


2011 ◽  
Vol 189-193 ◽  
pp. 2642-2646 ◽  
Author(s):  
Qian Li ◽  
Yi Bian ◽  
Zhi Ping Zhong ◽  
Gui Hua Liu ◽  
Ying Chen

The cold forging process of large module spur gear with four modules and 59mm breadth is performed by means of numerical simulation method. Two processes to forming such spur gears were compared by the simulation method, one is with the closed-die performing and extrusion in the finish-forging, the other is with divided-flow method in the finish-forging. Especially, the divided-flow method is analyzed in detail. The necessary reference and basis to realize practical cold precision forging process of spur gear with large modulus is provided eventually.


2021 ◽  
Vol 15 (2) ◽  
pp. 137-150
Author(s):  
Susanne Elisabeth Thürer ◽  
Anna Chugreeva ◽  
Norman Heimes ◽  
Johanna Uhe ◽  
Bernd-Arno Behrens ◽  
...  

AbstractThe current study presents a novel Tailored Forming process chain developed for the production of hybrid bearing bushings. In a first step, semi-finished products in the form of locally reinforced hollow profiles were produced using a new co-extrusion process. For this purpose, a modular tool concept was developed in which a steel tube made of a case-hardening steel, either C15 (AISI 1015) or 20MnCr5 (AISI 5120), is fed laterally into the tool. Inside the welding chamber, the steel tube is joined with the extruded aluminum alloy EN AW-6082. In the second step, sections from the compound profiles were formed into hybrid bearing bushings by die forging. In order to set the required forming temperatures for each material—aluminum and steel—simultaneously, a tailored heating strategy was developed, which enabled successful die forging of the hybrid workpiece to the desired bearing bushing geometry. Using either of the case-hardening steels in combination with aluminum, this novel process chain made it possible to produce intact hybrid bearing bushings, which showed both macroscopically and microscopically intimate material contact inside the compound zone.


2021 ◽  
Vol 11 (5) ◽  
pp. 2142
Author(s):  
Trung-Kien Le ◽  
Tuan-Anh Bui

Motorbike shock absorbers made with a closed die employ a tube-forming process that is more sensitive than that of a solid billet, because the tube is usually too thin-walled to conserve material. During tube forming, defects such as folding and cracking occur due to unstable tube forming and abnormal material flow. It is therefore essential to understand the relationship between the appearance of defects and the number of forming steps to optimize technological parameters. Based on both finite element method (FEM) simulations and microstructural observations, we demonstrate the important role of the number and methodology of the forming steps on the material flow, defects, and metal fiber anisotropy of motorbike shock absorbers formed from a thin-walled tube. We find limits of the thickness and height ratios of the tube that must be held in order to avoid defects. Our study provides an important guide to workpiece and processing design that can improve the forming quality of products using tube forming.


2015 ◽  
Vol 651-653 ◽  
pp. 627-632 ◽  
Author(s):  
Svetlana Ishkina ◽  
Bernd Kuhfuss ◽  
Christian Schenck

Rotary swaging is a well established cold forming process e.g. in the automotive industry. In order to modify the material properties by swaging systematically, a new process of swaging with asymmetrical strokes of the forming dies is investigated. The newly developed tools feature flat surfaces and do not represent the geometry of the formed part as in conventional swaging. Numerical simulation and physical tests are carried out with special regard to the resulting geometry, mechanical properties and the microstructure. During these tests copper wires with diameter d0=1 mm are formed. Regarding the microstructure in the longitudinal section of formed specimens, elongation of grains in the central part and grain size reduction in the boundary area are observed. Furthermore, this approach opens up new possibilities to configure the geometry of wires. 2D-simulation is applied and discussed in the paper to investigate change of the processed geometry (cross-section) and shear strain distribution during the rotary swaging process.


2008 ◽  
Vol 575-578 ◽  
pp. 174-179
Author(s):  
Juan Hua Su ◽  
Feng Zhang Ren ◽  
Lei Wang

This paper analyzes the forming process methods of fin used in CPU chip to emit heat. The whole process is blanking, the first forging forming, the second forging (sizing), and trimming. The chamfer design of CPU fin blank is simulated by finite element analysis. The optimized chamfer 1.6 mm is available. Semi-enclosed cold forging of progressive dies is put forward. The newly designed transfer unit is applied, which unifies the merit of high efficiency of the progressive dies and the high material-using ratio of the project die. Quick disassembly structure is designed and pins are used as quick disassembly pins by means of ball bearing bushing. The unique processing of the shearing scrap structure is adopted when designing the inverted trimming dies. Compared with the traditional die, the mechanization and electrization are realized to increase the production efficiency and get highly precise CPU fin.


2011 ◽  
Vol 264-265 ◽  
pp. 24-29 ◽  
Author(s):  
Seyed Mohammad Ebrahimi ◽  
Seyed Ali Asghar Akbari Mousavi ◽  
Mostafa Soltan Bayazidi ◽  
Mohammad Mastoori

Flow forming is one of the cold forming process which is used for hollow symmetrical shapes. In this paper, the forward flow forming process is simulated using the finite element method and its results are compared with the experimental process. The variation of thickness of the sample is examined by the ultrasonic tests for the five locations of the tubes. To simulate the process, the ABAQUS explicit is used. The effects of flow forming variables such as the angle of rollers and rate of feeding of rollers, on the external variables such as internal diameter, thickness of tube and roller forces are considered. The study showed that the roller force and surface defects were reduced with low feeding rate and low rollers attack angles. Moreover, the sample internal diameter increased at low feeding rate and low rollers attack angles. The optimum variables for flow forming process were also obtained.


2017 ◽  
Vol 107 (10) ◽  
pp. 708-713
Author(s):  
M. Prof. Liewald ◽  
L. Pasler

Mit dem neu entwickelten Verfahren, das Querfließpressen mit gleichzeitigem Verschieben kombiniert, lassen sich exzentrische Wellen oder kurbelwellenartige Bauteile durch Kaltfließpressen herstellen. Der Vorteil im Unterschied zur Verfahrenskombination von Stauchen und anschließendem Verschieben ist, dass das Querfließpressen ein Nachführen von Material während des Umformprozesses in die Umformzone ermöglicht. Aufgrund der verfahrensbedingten geringeren Zugspannungen in der Kurbelwange sind mit dem neuen Verfahren erweiterte Verfahrensgrenzen beim Versatz zu erwarten. Dieser Fachbeitrag beschreibt das Verfahrensprinzip, das Werkzeugkonzept und die numerische Auslegung des Prozesses.   The new technology of combined lateral extrusion and simultaneous shifting allows producing eccentric shafts or crankshaft-like components by cold forging. The advantage of lateral extrusion compared to an upsetting and subsequent shifting is the constant web thickness. For this, material is pushed into the forming zone during the forming process. It is expected that this will result in lower tensile stresses and thus lower damage in the crankshaft web. This paper describes the process, tooling concept and numerical simulation of the combined lateral extrusion and shifting process.


2015 ◽  
Author(s):  
Pei-Yong Li ◽  
◽  
Jun-jie Song ◽  
Cheng-fang Wang ◽  
Yun-sheng Mao ◽  
...  

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