Closed-Die Forging of Gear-Like Elements

1998 ◽  
Vol 120 (1) ◽  
pp. 34-41 ◽  
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.

Upper Bound Analysis of Axisymmetric, Closed-Die Forgings

1981 ◽  
Vol 103 (1) ◽  
pp. 109-112 ◽  
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.

scholarly journals Novel Method of Severe Plastic Deformation - Continuous Closed Die Forging: CP Aluminum Case Study

2018 ◽  
Vol 385 ◽  
pp. 302-307 ◽  
Author(s):  
Alexander P. Zhilyaev ◽  
Sandra Rodriguez ◽  
Jessica Calvo ◽  
Jose María Cabrera
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Pure Aluminum ◽  
Multidirectional Forging ◽  
Die Forging ◽  
Closed Die Forging ◽  
Accumulated Strain ◽  
Novel Method ◽  
Aluminum 1050

There is a large number of methods for severe plastic deformation (SPD). Multidirectional forging (MDF) is probably one of the most easily scalable for industrial application. In general, two main conditions need to be fulfilled for successful SPD processing: constant sample geometry and application of a quasi-hydrostatic pressure. The first condition is necessary for strain accumulation by repetitive deformation and the second one helps preventing cracking in the specimens with high accumulated strain. However, MDF is not providing quasi-hydrostatic condition in the processed sample. This paper reports a novel method for severe plastic deformation, namely continuous closed die forging (CCDF), which fulfils both requirements for the successful deformation of samples to a very high accumulated strain. Commercially pure aluminum (1050) was processed to a total strain of 24 by CCDF. After processing, the microstructure was refined down to a mean grain size of 0.78 μm. Tensile testing showed good mechanical properties: yield strength and ultimate tensile strength of the ultrafine-grained aluminum were 180 and 226 MPa, respectively. Elongation to rupture was about 18%. The microstructure, microhardness and grain boundary statistics are discussed with regard to the high mechanical properties of the UFG aluminum processed by this novel method.

Preform design in axial hot closed die forging by isothermal surface method. Part 1. Overview of preform design methods. Theoretical aspects and algorithm of preform shape design

2021 ◽  
pp. 214-220
Author(s):  
A.V. Vlasov ◽  
D.V. Krivenko ◽  
S.A. Stebunov ◽  
N.V. Biba ◽  
A.M. Dyuzhev
Keyword(s):  
Simulation Software ◽  
Preform Design ◽  
Mathematical Basis ◽  
Design Algorithm ◽  
Forming Simulation ◽  
Die Geometry ◽  
Die Forging ◽  
Closed Die Forging ◽  
Trial And Error Method ◽  
Preform Shape

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™.

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

1997 ◽  
Vol 67 (1-3) ◽  
pp. 83-88 ◽  
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

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

1989 ◽  
Vol 203 (1) ◽  
pp. 38-42 ◽  
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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