The influence of die shape on the flow deformation of extrusion forging

Wu, Chun-Yin; Hsu, Yuan-Chuan

doi:10.1016/s0924-0136(02)00030-4

Cited by 27 publications

(17 citation statements)

References 9 publications

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“…Regressional description of the shape changes and the force conditions at preparation forging is given in [5,6] which allows: (i) to choose appropriate height-to-diameter initial ratios to achieve the desired preparatory shapes and (ii) to evaluate the mean pressure and the force needed for extrusion forging and piercing. Some other authors have also investigated [7][8][9] the extrusion forging to verify UBET or FEM analyses and to show the metal flow in more detail but no equations for simple calculations are given there.…”

Section: Preparation Stepsmentioning

confidence: 99%

Numerical simulations of hot die forging processes using finite element method

Tomov¹,

Gagov²,

Radev³

2004

Journal of Materials Processing Technology

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Section: Preparation Stepsmentioning

confidence: 99%

Numerical simulations of hot die forging processes using finite element method

Tomov¹,

Gagov²,

Radev³

2004

Journal of Materials Processing Technology

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“…In the radial forging process, the friction factors between workpieces and tools were assumed to be constants. The friction stress was assumed to be the arctangent function of relative slide velocity, and the friction stress [9] F f could be represented as follows:…”

Section: Mathematical Modelmentioning

confidence: 99%

“…Three different types of punching are considered as parameters for designing the die, so the outline of the radially extruded flange, and the relationship between the parameters associated with the die and the warping can be defined. In 2002, Wu et al [9] developed an extrusion forging model to analyze the effect on the deformation and movement of the billet during metal forming, by considering the outline of the die. Tapered holes and rounded corners of the upper die effect the forming load and distribution of the stress and strain.…”

Section: Introductionmentioning

confidence: 99%

A Study on the Warping Problems of Thin Flange under the Radial Forging Processes by FEM and Experiments

Hsiang

2004

Int J Adv Manuf Technol

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During metal forging, warping can easily occur on the edge of the thin flange, causing it to fold, affecting the sustainability of the application of the flange. This investigation proposes a chamfer design for the die and the taper design for the ring gap, to eliminate warping. First, the radial forging process of work-hardened materials is simulated, the phenomenon of flange warping is analyzed, and the accuracy of the simulation is experimentally verified. Secondly, the materials, lubricants and the height of the ring gap of the die are set as fixed parameters, and the analytical results for dies with rounded corner, chamfered and a tapered of the ring gap, are compared. The experiments and simulation confirm that the problem of flange warping can be solved effectively. The results are as follows.1. When the die has a rounded corner and R = 2 mm, serious warping and breaking creases are observed alongs the rim of the flange. 2. When the die is designed with a chamfer, experiments and simulation both demonstrate that warping is reduced slowly as the chamfer value increases. 3. When the die corner has a radius of R = 2 mm, and has a taper shape between the rounded corner and the ring gap, experiments and simulation both indicate that warping declines as the tapering increases. However, as the contact area between the raw material and the die increases, its forming load increases with the taper angle.All of these results indicate that the solution to the warping problem proposed herein is feasible and effective, and that the results of this study represent useful references for design dies for radial forging.

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“…They also elucidated the relationship among the relevant parameters of the die, the warping of the flange and the outline of the flange. In 2002, Wu and Hsu (2002) adopted an extrusion forging model to analyze the effect of the shape of the die on the deformation behavior and the flow pattern of the billet; they explained the relationship between the die and the forming load. In 2002, Im et al (2002) performed an experiment on AL6061-O aluminum alloy, using various lubricants, and analyzed the results based on the backward extrusion model.…”

Section: Introductionmentioning

confidence: 99%