Modified Upper Bound Elemental Technique (MUBET) for Preform Design in Closed Die Forging

Methods of preform design in hot-die forging are analyzed. It is noted that despite numerous works in this fi eld, preform design is still often based on the trial-and-error method. The isothermal surfaces method for preform design is proposed and its mathematical basis is considered. The procedure for determining of the preform shape is given. The design algorithm uses the QForm metal forming simulation software to build isothermal surfaces and check in the quality of the designed die geometry by finite element modeling, as well as specially developed version of the QFormDirect CAD based on SpaceClaim™.

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An upper-bound analysis of the closed-die forging of spur gears

Journal of Materials Processing Technology ◽

10.1016/s0924-0136(96)02823-3 ◽

1997 ◽

Vol 67 (1-3) ◽

pp. 83-88 ◽

Cited By ~ 4

Author(s):

Haeyong Cho ◽

Jaechan Choi ◽

Gyusik Min ◽

Young Choi ◽

Jongung Choi

Keyword(s):

Upper Bound ◽

Spur Gears ◽

Upper Bound Analysis ◽

Die Forging ◽

Closed Die Forging ◽

Bound Analysis

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Three-Dimensional Analysis of Closed-Die Forging Processes Part 2: Applications

Proceedings of the Institution of Mechanical Engineers Part B Journal of Engineering Manufacture ◽

10.1243/pime_proc_1989_203_044_02 ◽

1989 ◽

Vol 203 (1) ◽

pp. 38-42 ◽

Cited By ~ 2

Author(s):

C F Lugora ◽

A N Bramley

Keyword(s):

Dimensional Analysis ◽

Upper Bound ◽

Reasonable Agreement ◽

Three Dimensional ◽

Die Forging ◽

Closed Die Forging ◽

Forging Load

A generalized procedure for the analysis of three-dimensional forging problems has been proposed using the upper bound elemental technique. This analysis allows the subdivision of a forging into elementary simple regions. In this second part of the series, the model is applied to predict forging load in a selected category of closed-die forging processes. Experiments are carried out and a reasonable agreement with theory is found.

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Closed-Die Forging of Gear-Like Elements

Journal of Manufacturing Science and Engineering ◽

10.1115/1.2830108 ◽

1998 ◽

Vol 120 (1) ◽

pp. 34-41 ◽

Cited By ~ 5

Author(s):

A. El-Domiaty ◽

M. Shabara ◽

M. Al-Ansary

Keyword(s):

Upper Bound ◽

Pure Aluminum ◽

Experimental Results ◽

Frictional Stress ◽

Die Geometry ◽

Die Forging ◽

Closed Die Forging ◽

Theoretical Predictions ◽

Upper Bound Technique ◽

Forging Die

Closed die forging of spur gears is investigated using the slab method and the upper bound technique. The tooth regions are approximated by prismatic rectangular sections. The velocity field comprising three unit deformation regions is used. A constant frictional stress between workpiece and forging die is assumed. The average punch pressure normalized by the flow stress of the gear material is determined theoretically and compared with experimental results. The experimental work is carried out on a commercial pure aluminum (Al 1100) at room temperature. The forging process is carried out using one die geometry without using any additional blocker (preform) dies. The theoretical predictions of forging pressures using slab and upper bound methods agree fairly well with the experimental results.

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Upper Bound Analysis of Axisymmetric, Closed-Die Forgings

Journal of Engineering for Industry ◽

10.1115/1.3184450 ◽

1981 ◽

Vol 103 (1) ◽

pp. 109-112 ◽

Cited By ~ 3

Author(s):

P. Dadras

Keyword(s):

Velocity Field ◽

Upper Bound ◽

Deformation Zone ◽

Admissible Velocity ◽

Upper Bound Analysis ◽

Die Forging ◽

Closed Die Forging ◽

Theoretical Predictions ◽

Experimental Values ◽

Bound Analysis

A kinematically admissible velocity field for axisymmetric closed die forging is proposed. The forging power and load are calculated and compared with experimental values. It is found that the theoretical predictions give estimates that are substantially higher than actual loads and powers. Also, the effect of different parameters on the height and shape of the deformation zone is investigated and it is shown that the height is independent of flash thickness and length. The angle of convergence of flow from the die to the flash decreases as the flash thickness is increased.

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