Forming Mechanism of Folding Defect within Closed Die Forming Car Steering Knuckle

2011 ◽  
Vol 704-705 ◽  
pp. 240-244 ◽  
Author(s):  
De Ying Zhao ◽  
Lian Dong Zhang ◽  
Li Na Sun
Keyword(s):  
Extrusion Process ◽  
Steering System ◽  
Forming Process ◽  
Forming Mechanism ◽  
Lateral Extrusion ◽  
Folding Defect ◽  
Material Utilization ◽  
Punch Shape ◽  
Die Forming ◽  
Shape And Size

Steering knuckle is the key part of vehicle steering system. The forming technology combined closed die pre-forging with open finish-forging has some advantages such as higher material utilization ratio and lower forming forces and so on. While simulating the closed die extrusion forming process of car steering knuckle, folding defect emerges on the contact area of Branch I and lower punch in the lateral extrusion process. The forming mechanism of the folding defect is studied by numerical simulations and experiments, which mainly consider the influence of lower punch shape and size, extrusion speed and friction conditions to folding length. The results show that the main factors that affect folding defects are the lower punch shape and size. Keywords: steering knuckle, folding defect, closed die forming, numerical simulation, experiment study

The Technological Optimization of Closed Multiple-Ram Forging for Draw Rod

2010 ◽  
Vol 29-32 ◽  
pp. 2339-2344
Author(s):  
Chun Dong Zhu ◽  
Tai Liang Dai ◽  
Hui Wang
Keyword(s):  
Numerical Simulation ◽  
Steering System ◽  
Original Material ◽  
Forming Process ◽  
High Quality ◽  
Mechanical Parts ◽  
Optimal Technology ◽  
Simulation Results ◽  
Material Utilization ◽  
Open Die Forging

Draw rod is one of the main mechanical parts of vehicle steering system，which is required extremely high quality. At present the way to produce the draw rod is machining after common open-die forging. This technology will produce big flashings，damage the metal’s fibrous structure and reduce the material utilization. In this essay, we will use the technology of closed multiple-ram forging to produce it. We will utilize numerical simulation on several blanks through numerical simulation combined with experiments. In this way, the defects that some parts of the blank are folded and cannot fill well during forming process can be effectively avoided. Besides, there will be free of flashing and the draw rod forgings do not need to be cut. The weight of the original blank will be about 3.5 kg after being optimized, down by 36.4 percent compared with that of original material about 5.5 kg. And we will make different settings for the loading way of the plunger chips during the forming process, then compare with the simulation results and ultimately find out the best loading way. At last, we will verify the feasibility of such an optimal technology through experiments on the material-lead.

scholarly journals Study on strong spinning preparation method and mechanism of the industrial pure titanium ultrafine crystallization

2019 ◽  
Vol 14 ◽  
pp. 155892501989525
Author(s):  
Yu Yang ◽  
Yanyan Jia
Keyword(s):  
Heat Treatment ◽  
High Performance ◽  
Pure Titanium ◽  
Grain Structure ◽  
Theoretical Research ◽  
Ultrafine Grain ◽  
Forming Process ◽  
Spinning Process ◽  
And Performance ◽  
Material Utilization

Ultrafine crystallization of industrial pure titanium allowed for higher tensile strength, corrosion resistance, and thermal stability and is therefore widely used in medical instrumentation, aerospace, and passenger vehicle manufacturing. However, the ultrafine crystallizing batch preparation of tubular industrial pure titanium is limited by the development of the spinning process and has remained at the theoretical research stage. In this article, the tubular TA2 industrial pure titanium was taken as the research object, and the ultrafine crystal forming process based on “5-pass strong spin-heat treatment-3 pass-spreading-heat treatment” was proposed. Based on the spinning process test, the ultimate thinning rate of the method is explored and the evolution of the surface microstructure was analyzed by metallographic microscope. The research suggests that the multi-pass, medium–small, and thinning amount of spinning causes the grain structure to be elongated in the axial and tangential directions, and then refined, and the axial fiber uniformity is improved. The research results have certain scientific significance for reducing the consumption of high-performance metals improving material utilization and performance, which also promote the development of ultrafine-grain metals’ preparation technology.

scholarly journals Process chain for the manufacture of hybrid bearing bushings

2021 ◽  
Vol 15 (2) ◽  
pp. 137-150
Author(s):  
Susanne Elisabeth Thürer ◽  
Anna Chugreeva ◽  
Norman Heimes ◽  
Johanna Uhe ◽  
Bernd-Arno Behrens ◽  
...  
Keyword(s):  
Extrusion Process ◽  
Steel Tube ◽  
Case Hardening ◽  
Process Chain ◽  
Forming Process ◽  
Die Forging ◽  
Material Contact ◽  
Hybrid Bearing ◽  
Case Hardening Steel ◽  
Tailored Forming

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.

The Strain Analysis at the Broadening Stage of the Hollow Railway Axle by Multi-Wedge Cross Wedge Rolling

2014 ◽  
Vol 494-495 ◽  
pp. 457-460 ◽  
Author(s):  
Bin Hu ◽  
Xue Dao Shu ◽  
Peng Hui Yu ◽  
Wen Fei Peng
Keyword(s):  
Production Efficiency ◽  
Strain Analysis ◽  
Cross Wedge Rolling ◽  
Forming Process ◽  
Element Analysis ◽  
Forming Mechanism ◽  
Railway Axle ◽  
The Finite Element Analysis ◽  
Scientific Significance ◽  
Deform 3D

The paper is based on the newest hollow railway axle, which utilizes the Pro/E designed multi-wedge cross wedge rolling (MCWR) model, utilizes the finite element analysis software DEFORM-3D to complete the numerical simulation about the whole stage of the hollow railway axle forming process, and analyzes the strain rule at the broadening stage of the hollow railway axle, especially conducts a detailed research on forming character into the strain rule at the multi-wedge transition stage, and finally gets the strain forming mechanism of the hollow railway axle at the broadening stage. The result of the research on the strain rule poses great scientific significance on enhancing the product quality and the production efficiency of the hollow railway axle, and improving the theory of multi-wedge cross wedge rolling.

Flexible Stretch Forming Technology for Sheet Metal Based on Discrete-Gripper and Multi-Point Die

2014 ◽  
Vol 556-562 ◽  
pp. 460-463 ◽  
Author(s):  
Xue Chen ◽  
Ming Zhe Li ◽  
Wen Hua Liu ◽  
Zhi Qiang Hou
Keyword(s):  
Sheet Metal ◽  
Experimental Results ◽  
Shape Error ◽  
Stretch Forming ◽  
Forming Process ◽  
Structural Composition ◽  
Forming Technology ◽  
Working Principle ◽  
Material Utilization

To solve the problem of low material utilization in traditional stretch forming process, a flexible stretch forming method was proposed, which can be realized by interaction of the multi-point stretch forming die with discrete-gripper stretch forming machine. The principle and characteristics of sheet metal flexible stretch forming technology was introduced, structural composition and working principle of the multi-point stretch forming die and discrete-gripper stretch forming machine were expounded, and the technology experiments was carried out with a self-designed flexible stretch forming technology equipment for sheet metal. The experimental results indicate that structure of multi-point stretch forming die and discrete-gripper stretch forming machine are reasonable, and flexible stretch forming technology can be realized by above-mentioned die and machine, stretch forming parts has a good quality and its shape error can satisfy requirements of production.

Querfließpressen und Verschieben*/Lateral extrusion and shifting

2017 ◽  
Vol 107 (10) ◽  
pp. 708-713
Author(s):  
M. Prof. Liewald ◽  
L. Pasler
Keyword(s):  
Numerical Simulation ◽  
New Technology ◽  
Cold Forging ◽  
Forming Process ◽  
Tensile Stresses ◽  
Lateral Extrusion

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.

Numerical and experimental analysis on cold-forming and spring-back of hull plate

2018 ◽  
Vol 233 (3) ◽  
pp. 561-569 ◽  
Author(s):  
Wei Shen ◽  
Renjun Yan ◽  
Shuangying Li
Keyword(s):  
Three Dimensional ◽  
Dimensional Accuracy ◽  
Ship Hull ◽  
Laser Forming ◽  
Successive Approximation Method ◽  
Spring Back ◽  
Forming Process ◽  
Cold Forming ◽  
Thick Plates ◽  
Forming Mechanism

Ship hull structures are fabricated by curved thick plates before they are welded together. There are traditional methods such as, line heating and laser-forming methods for plate bending. However, it is recognized that the hot-forming technology causes a series of troubles on doubly or multiple curved plates. Multi-point forming mechanism with square press heads is a new forming process for three-dimensional ship hull plate. Cold-forming has a high dimensional accuracy but results in spring-back. The spring-back process of curved thick plates in the finite element method is analyzed and the predicted results are compared with the test results in the present paper. To ensure the forming precision, the successive approximation method is also developed and verified to control the spring-back.

scholarly journals Extension of the forming limits of extrusion processes in sheet-bulk metal forming for production of minute functional elements

2020 ◽  
Vol 7 ◽  
pp. 9 ◽  
Author(s):  
Florian Pilz ◽  
Johannes Henneberg ◽  
Marion Merklein
Keyword(s):  
Sheet Metal ◽  
Metal Forming ◽  
Extrusion Process ◽  
Process Conditions ◽  
Functional Elements ◽  
Bulk Metal ◽  
Bulk Metal Forming ◽  
Lateral Extrusion ◽  
Component Design ◽  
Tailored Surfaces

Increasing demands in modern production pose new challenges to established forming processes. One approach to meet these challenges is the combined use of established process classes such as sheet and bulk forming. This innovative process class, also called sheet-bulk metal forming (SBMF), facilitates the forming of minute functional elements such as lock toothing and gear toothing on sheet-metal bodies. High tool loads and a complex material flow that is hard to control are characteristic of SBMF. Due to these challenging process conditions, the forming of functional elements is often insufficient and necessitates rework. This negatively affects economic efficiency. In order to make use of SBMF in industrial contexts, it is necessary to develop measures for improving the forming of functional elements and thereby push existing forming boundaries. This paper describes the design and numerical replication of both a forward and a lateral extrusion process so as to create involute gearing in combination with carrier teeth. In a combined numerical-experimental approach, measures for extending the die filling in sheet-metal extrusion processes are identified and investigated. Here, the focus is on approaches such as process parameters, component design and locally adjusted tribological conditions; so-called ‘tailored surfaces’. Based on the findings, fundamental mechanisms of action are identified, and measures are assessed with regard to their potential for application. The examined approaches show their potential for improving the forming of functional elements and, consequently, the improvement of geometrical accuracies in functional areas of the workpieces.

scholarly journals Performance of Thermo-Mechanically Processed AA7075 Alloy at Elevated Temperatures—From Microstructure to Mechanical Properties

Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 884 ◽  
Author(s):  
Seyed Vahid Sajadifar ◽  
Emad Scharifi ◽  
Ursula Weidig ◽  
Kurt Steinhoff ◽  
Thomas Niendorf
Keyword(s):  
Mechanical Properties ◽  
Elevated Temperatures ◽  
Tensile Tests ◽  
Uniaxial Tensile ◽  
Forming Process ◽  
Softening Mechanism ◽  
Rate Dependent ◽  
Heat Treated ◽  
Different Temperatures ◽  
Die Forming

This study focuses on the high temperature characteristics of thermo-mechanically processed AA7075 alloy. An integrated die forming process that combines solution heat treatment and hot forming at different temperatures was employed to process the AA7075 alloy. Low die temperature resulted in the fabrication of parts with higher strength, similar to that of T6 condition, while forming this alloy in the hot die led to the fabrication of more ductile parts. Isothermal uniaxial tensile tests in the temperature range of 200–400 °C and at strain rates ranging from 0.001–0.1 s−1 were performed on the as-received material, and on both the solution heat-treated and the thermo-mechanically processed parts to explore the impacts of deformation parameters on the mechanical behavior at elevated temperatures. Flow stress levels of AA7075 alloy in all processing states were shown to be strongly temperature- and strain-rate dependent. Results imply that thermo-mechanical parameters are very influential on the mechanical properties of the AA7075 alloy formed at elevated temperatures. Microstructural studies were conducted by utilizing optical microscopy and a scanning electron microscope to reveal the dominant softening mechanism and the level of grain growth at elevated temperatures.

Effect of Punch Surface Topography on Friction in Micro Combined Forward and Backward Extrusion of Brass

2014 ◽  
Vol 939 ◽  
pp. 239-244 ◽  
Author(s):  
Chao Cheng Chang ◽  
Cheng Ping Siao
Keyword(s):  
Surface Topography ◽  
Metal Forming ◽  
Electrical Discharge Machining ◽  
Extrusion Process ◽  
Machining Processes ◽  
Forming Process ◽  
Factors Affecting ◽  
Backward Extrusion ◽  
Micro Electrical Discharge Machining ◽  
Metal Forming Process

Friction is one of the key factors affecting the metal forming process. If the friction effects of the process can be accurately modeled, it is able to improve simulations and help the research and development of the metal forming process. This study used cylindrical brass (JIS C2600) billets with the height and diameter of 1.1 mm for conducting the experiments of the micro combined forward and backward extrusion. The purpose of the study was to investigate the effects of punch surface topography on friction in the process. Four surface topography conditions for 0.8 mm diameter punches were prepared by grinding, polishing, grooving and micro electrical discharge machining processes. By comparing the ratio of the cup height to rod length of the extruded cups with the calibration curves established by simulations, the friction factor was estimated in a range from 0.3 to 0.6. The results showed that the punch surface topography significantly affect the friction in the extrusion process. The predicted loads using the estimated friction factors were in good agreement with the experimental results.

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