Bulk Deformation

2013 ◽  
pp. 103-161
Keyword(s):  
Hot Extrusion ◽  
High Energy ◽  
Ring Rolling ◽  
Cold Forging ◽  
Bulk Deformation ◽  
High Energy Rate ◽  
Precision Forging ◽  
Die Forging ◽  
Closed Die Forging ◽  
Deformation Processes

Abstract This chapter discusses bulk deformation processes and how they are used to reshape metals and refine solidification structures. It begins by describing the differences between hot and cold working along with their respective advantages. It then discusses various forging methods, including open-die and closed-die forging, hot upset and roll forging, high-energy-rate forging, ring rolling, rotary swaging, radial and orbital forging, isothermal and hot-die forging, precision forging, and cold forging. The chapter also includes information on cold and hot extrusion and drawing operations.

Numerical Simulation Analysis on Cold Closed-Die Forging of Differential Satellite Gear in Car

2008 ◽  
Vol 575-578 ◽  
pp. 517-524 ◽  
Author(s):  
Yao Zong Zhang ◽  
Jian Bo Huang ◽  
Xue Lin ◽  
Quan Shui Fang
Keyword(s):  
Numerical Simulation ◽  
Simulation Analysis ◽  
Simulation Software ◽  
Bevel Gear ◽  
Cold Forging ◽  
Forging Process ◽  
Die Forging ◽  
Closed Die Forging ◽  
Forming Defects ◽  
Deform 3D

The cold closed-die forging process of the gear is a kind of new technique of the precise forming of gear in recent years. In this paper, the cold closed-die forging process of differential satellite gear in car was analyzed through numerical simulation method. Forming mold was designed with Pro/E Wildfire2.0 which included four components : upper punch, lower punch, tooth shape upper die and lower die for Normal Cone. The three-dimensional models of satellite bevel gear mould were built and imported into numerical simulation software DEFORM-3D. Because the gear has the uniform circumferential features, in order to save time and improve the accuracy, only one tooth was simulated, and the full simulation outcome of 10 teeth was mirrored from this one. Through the numerical simulation analysis of DEFORM-3D, the instantaneous deformation and stress filed were gained. Forming defects were forecasted and the cold closed-die forging rule for satellite gear used in car was obtained which can provide effective references for no-flash cold forging process of planet bevel gear and the mold design.

The Present Situation and Developing Trends of Hot Closed-Die Forging

2015 ◽  
Vol 1094 ◽  
pp. 365-368
Author(s):  
Qi Liu ◽  
Xu Guang ◽  
Shi Xuan Sun
Keyword(s):  
Machine Building ◽  
Production Costs ◽  
Research Issues ◽  
Slowing Down ◽  
Research Fields ◽  
Precision Forging ◽  
Die Forging ◽  
Closed Die Forging ◽  
New Ideas ◽  
New Research

Due to its advantages including high quality of the forging parts and low production costs,hot closed-die forging (HCDF) play an essential role in the machine building industry. However, in recent decades, the pace of its development is gradually slowing down. In the hope of drawing up some new ideas about future development of the HCDF, this paper presents a brief overview of it. This study roughly prospects several potential research issues of the HCDF. Some new research fields such as precision forging, combined forging and numerical simulation have been shown. Challenges and possible response to them have been discussed.

An Experimental and Numerical Investigation into Forming Force Reduction in Precision Gear Forging

2014 ◽  
Vol 622-623 ◽  
pp. 165-173 ◽  
Author(s):  
Nicholas J. Politis ◽  
Denis J. Politis ◽  
Catrin Mair Davies ◽  
Jian Guo Lin ◽  
Trevor A. Dean
Keyword(s):  
Peak Load ◽  
Maximum Load ◽  
Fe Model ◽  
Precision Forging ◽  
Die Forging ◽  
Closed Die Forging ◽  
Force Reduction ◽  
Tool Set ◽  
Experimental Trials ◽  
The Cost

A significant factor in the cost of industrial machinery for precision forging is the maximum load required to fully forge the final shape of components. Typically in a precision forging process, the required load increases greatly towards the end of the stroke. This study focuses on reducing the final sharp increase in load encountered in a typical closed die forging setup. A technique of reducing the peak load in the forging of gears is proposed, named the Peripheral Relief (PR) method. A gear forging tool set has been designed and manufactured. A number of experimental trials have been performed using model materials to investigate the force reduction technique. An efficient and simplified FE model has been developed to evaluate the effects of the PR method. The experimental load characteristics are compared to the simulated results. The method has been found, both numerically and experimentally, to significantly reduce the peak load encountered at the end of the forging stroke compared to current closed die forging techniques.

Simulation and Experiment of Cold Forging for Spur Gear Based on Local Loading

2011 ◽  
Vol 268-270 ◽  
pp. 241-246 ◽  
Author(s):  
Feng Xu ◽  
Ke Min Xue ◽  
Ping Li ◽  
Dong Mei Gong ◽  
Gang Chao Wang ◽  
...  
Keyword(s):  
Spur Gear ◽  
Cold Forging ◽  
Spur Gears ◽  
Stress Distributions ◽  
Local Loading ◽  
Forming Technology ◽  
Die Forging ◽  
Closed Die Forging ◽  
Simulation And Experiment ◽  
Physics Experiment

The cold closed-die forging of spur gears brings the problems of great forming forces , low life of the dies and insufficent corner filling. The two-step forming technology is presented. First, the billet is pre-forged by closed-die forging for getting most of tooth profile. Second, the gear is finish-forging by local loading. The finite element method is used to simulate the cold forging process.The strain distributions, the stress distributions, velocity distributions and load-stroke curve are investigated.. The simulation results show that the technology can guarantee the full filling effect, and decrease the forming force remarkably. The results of simulation and analysis were verified by the physics experiment.

Research on Closed Die Forging Process of Car Steering Knuckle

2008 ◽  
Vol 575-578 ◽  
pp. 204-209 ◽  
Author(s):  
De Ying Zhao ◽  
Lian Dong Zhang ◽  
Hui Xue Sun
Keyword(s):  
Numerical Simulation ◽  
High Energy ◽  
Extrusion Pressure ◽  
Forming Process ◽  
Forging Process ◽  
Dimensional Precision ◽  
Die Forging ◽  
Closed Die Forging ◽  
Plastic Forming ◽  
Die Extrusion

Steering knuckle, which has strict requirements with regard to dimensional precision and quality, is a key component in cars. Conventional plastic forming methods are involved with intricate procedures and high energy consumptions. Normally, a 40 MN hot die forging press or a 100 KJ electro-hydraulic hammer is required to produce the steering knuckle. Closed die forging, which is a new precision forming technology developed in recent years, has some virtues, such as good mechanical properties, easy to form and improving of metal plastic deformation. Aiming at Jetta steering knuckle in this paper, the technology of two forging steps in one heat is presented. This technology is mainly composed of precision pre-forging, which is a closed die extrusion with the extrusion belt, and open finish-forging. The pre-forging process and finish-forging process are numerically simulated using the FEM software DEFORM-3D. For the closed die extrusion forming process, which is the key component of the technology, some key problems were researched, such as the flowing and filling regularity, extrusion-belt length, punch size, punch movement, lubrication and the relationship between the clamping pressure and the extrusion pressure. For the finish-forging process, the flowing and filling regularity of the finish-forging part was studied to verify the correct shape and dimension of the pre-forging part. Numerical simulation with regard to the pre-forging process shows that the closed die forging can not only help to form the pre-forging part, but also decrease the extrusion pressure to be less than 8 MN, extend the mould’s service life and increase the utilization ratio of materials to be more than 75%. Numerical simulation of the finish-forging process shows that the pre-forging part design is rational. In addition, the forging experiments were carried out using the dies designed in particular. The experiments show that the technology is feasible and can markedly improve the mechanical property of the forging piece.

Study on the Cold Closed-Die Forging of Planetary Bevel Gears

2013 ◽  
Vol 803 ◽  
pp. 321-325
Author(s):  
Feng Kang ◽  
E Chuan Yang ◽  
Yan Bin Wang ◽  
Qiang Chen ◽  
Da Yu Shu
Keyword(s):  
Numerical Simulation ◽  
High Precision ◽  
Cold Forging ◽  
Dimensional Precision ◽  
Bevel Gears ◽  
Die Forging ◽  
Closed Die Forging ◽  
Die Stress

Taking the Planetary Bevel Gears as an object, the characteristic of cold Closed-die Forging was studied. By Using the FEM, the flowing rule of metal in the process of cold forging were analyzed, which is composed of dual-direction extrusion, upsetting and filling the gear form. The results show that each district of cavity was filled completely at the end of forging, without corner collapse, fold or crack. Taken the lower die as an example, the distribution of die stress was also analyzed. The results of numerical simulation were proved by the experiments, meanwhile the high precision and quality forging was formed. To the gears, the cold closed-die forging can not only ensure the dimensional precision, but also improve the capability of the gear, while obviously reduce materials consumption.

Finite Element Analysis and Optimization of Deformation Behavior for Spur Gear Warm Forging Process

2010 ◽  
Vol 148-149 ◽  
pp. 854-858
Author(s):  
Shu Bo Xu ◽  
Cai Nian Jing ◽  
Ke Ke Sun ◽  
Guo Cheng Ren ◽  
Gui Qing Wang
Keyword(s):  
Finite Element ◽  
Spur Gear ◽  
Spur Gears ◽  
Element Analysis ◽  
Helical Gears ◽  
Forging Process ◽  
Precision Forging ◽  
Die Forging ◽  
Closed Die Forging ◽  
Warm Forging

Recent years have therefore seen growing interest in gear precision forging to net-shape form of forge bevel, spur and helical gears, as an alternative to conventional manufacturing. In this paper, gear precision forging processes are simulated by using metal forming finite element code DEFORM-3D. The investigations of gear precision forging processes are conducted with perform forging and final forging processes. The processes of completely closed-die forging, moving-die forging and central divided flow forging processes are investigated for spur gears. The effect of different processes on the distribution of effective stress in the workpieces and forging loads are given. The purpose of this study is to introduce a new method, a so-called floating-relief method which applied to the forging of spur gears. It indicated that the flowing properties of the gear billet have a higher improve than that of conventional forging process. And the forging load obtained by using this new precision forging technology is decline sharply. The floating-relief method for gear precision forging is a sound process in the practical application.

The Precision Forging Experiment of Mg Alloy Drop Forging Using Computer Simulation

2014 ◽  
Vol 1064 ◽  
pp. 175-180
Author(s):  
Mária Kapustová ◽  
Jozef Bílik
Keyword(s):  
Rapid Development ◽  
Production Costs ◽  
Precision Forging ◽  
Ferrous Metals ◽  
Die Forging ◽  
Numeric Simulation ◽  
Closed Die Forging ◽  
Alloy Type ◽  
Non Ferrous Metals ◽  
Increasing Demand

Rapid development of automotive industry brings increasing demand for die forgings made from non-ferrous metals. Market economy stimulates drop forges to produce forged pieces of highest quality and dimension precision with the accent on reduction in production costs. Precision die forging without flash belongs to progressive and economical technologies of die forgings production. This paper describes an experiment of precision forging in closed die of magnesium alloy type AZ 31. Given alloy type Mg-Al-Zn is suitable for bulk forming and is characterized by good hot formability. Achieved results may be applied in practice at production of longitudinal shaped forgings e.g. levers and connecting rods. In order to verify a design of closed die forging technology regarding the lever-shaped forged piece, simulation program MSC.SuperForge was used. Numeric simulation was significantly helpful at optimization of semi-product shape and dimensions and confirmed correct plastic flow of material in closed die cavity. The objective of this contribution was to point out current trends in searching for economical measures at production of die forgings from alloys of non-ferrous metals.

Evaluation of the Mechanical Properties of Carbon Nanotube (CNT) Reinforced Aluminum (6061) Composites Using Closed Die Forging

2020 ◽  
Vol 843 ◽  
pp. 33-38
Author(s):  
J.S.Suresh Babu ◽  
Jun Park ◽  
Chung Gil Kang
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Compressive Strength ◽  
Large Deformations ◽  
High Energy ◽  
Cold Upsetting ◽  
Die Forging ◽  
Closed Die Forging ◽  
Energy Ball ◽  
Upsetting Test

In this study, the closed die forging of aluminium based compoistes reinfoced with CNTs (1vol% and 3vol%) were investigated. Initially, the composites were fabricated using high energy ball milling followed by compaction and sintering. The microstructural results showed that finer grain size and homogeneous dispersion of CNTs were obtained. Composites with up to 97% densification were produced when fine open porosities were removed by closed die forging. The results imply that the hardness and compressive strength of composites with 3vol.% of CNTs has improved without any deterioration. In addition, workability behaviors of composites were investigated by cold upsetting test. For that pore reopening test was performed to confirm the closure of micro-pores after the closed die forged, and to further analyze the densification of the composites. Typical cases, as the pores were not re-opened even after increasing the strain, additional forming is possible up to large deformations.

Milling Curves Influence in Ring Rolling Processes

2014 ◽  
Vol 622-623 ◽  
pp. 956-963 ◽  
Author(s):  
Luca Giorleo ◽  
Elisabetta Ceretti ◽  
Claudio Giardini
Keyword(s):  
Numerical Approach ◽  
The Other ◽  
Ring Rolling ◽  
Roll Speed ◽  
Forming Process ◽  
Industrial Case Study ◽  
Industrial Environment ◽  
Ring Shape ◽  
Deformation Processes

Ring Rolling is a complex hot forming process used for the production of shaped rings, seamless and axis symmetrical workpieces. The main advantage of workpieces produced by ring rolling, compared to other technological processes, is given by the size and orientation of grains, especially on the worked surface which give to the final product excellent mechanical properties. In this process different rolls (Idle, Axial, Guide and Driver) are involved in generating the desired ring shape. Since each roll is characterized by a speed law that can be set independently by the speed law imposed to the other rolls, an optimization is more critical compared with other deformation processes. Usually, in industrial environment, a milling curve is introduced in order to correlate the Idle and Axial roll displacement, however it must be underlined that different milling curves lead to different loads and energy for ring realization. In this work an industrial case study was modeled by a numerical approach: different milling curves characterized by different Idle and Axial roll speed laws (linearly decreasing, constant, linearly increasing) were designed and simulated. The results were compared in order to identify the best milling curve that guarantees a good quality ring (higher diameter, lower fishtail) with lower loads and energy required for manufacturing.

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