Theoretical investigation of the process of cold extrusion of rods from unplasticized metal powders. III. Extrusion pressure

1987 ◽  
Vol 26 (7) ◽  
pp. 519-523
Author(s):  
A. V. Stepanenko ◽  
L. A. Isaevich ◽  
A. A. Veremeichik ◽  
T. A. Medvedeva
Keyword(s):  
Theoretical Investigation ◽  
Extrusion Pressure ◽  
Cold Extrusion ◽  
Metal Powders

Calculation of the process of cold extrusion of tubes from metal powders. II. Reverse extrusion

1989 ◽  
Vol 28 (5) ◽  
pp. 355-358
Author(s):  
A. V. Stepanenko ◽  
L. A. Isaevich ◽  
A. A. Veremeichik
Keyword(s):  
Cold Extrusion ◽  
Metal Powders

Calculation of the process of cold extrusion of tubes from metal powders. I. Direct extrusion

1989 ◽  
Vol 28 (3) ◽  
pp. 160-163
Author(s):  
A. V. Stepanenko ◽  
L. A. Isaevich ◽  
A. A. Veremeichik
Keyword(s):  
Cold Extrusion ◽  
Metal Powders ◽  
Direct Extrusion

Effects of Type of Lubricant in Cold Extrusion of Sintered Preforms

1983 ◽  
Vol 105 (2) ◽  
pp. 128-131
Author(s):  
T. Tabata ◽  
S. Masaki ◽  
K. Hosokawa
Keyword(s):  
Copper Powder ◽  
Crack Formation ◽  
Solid Lubricants ◽  
Extrusion Ratio ◽  
Extrusion Pressure ◽  
Cold Extrusion ◽  
Sintered Copper ◽  
Dry Film

Four types of lubricant, i.e., dry film, liquid, powdered solid and liquid with powdered solid lubricants, were evaluated for cold extrusion of sintered copper powder preforms. Effects of the lubricants on extrusion pressure, densification and crack formation were examined with respect to variations of density of the preforms, extrusion ratio and die angle. It was found that liquid and liquid with powdered solid lubricants were not suitable for extrusion of sintered preforms.

A Refined Analytical Model for Hydrodynamic Lubrication of Cold Extrusion and Its Comparison With Experiment

1982 ◽  
Vol 104 (1) ◽  
pp. 46-52 ◽  
Author(s):  
S. M. Mahdavian
Keyword(s):  
Analytical Model ◽  
Castor Oil ◽  
Hydrodynamic Lubrication ◽  
Work Zone ◽  
Extrusion Pressure ◽  
Cold Extrusion ◽  
Viscous Heating ◽  
Theoretical Estimation ◽  
Comparison With Experiment ◽  
Inlet Zone

In a refined analytical model for the hydrodynamic lubrication of cold extrusion, effects of viscous heating in the inlet zone and surface temperature in the work zone are included to estimate extrusion pressure for both unsteady and steady lubrication. An experimental study indicates that a hydrodynamic lubricant film may be formed by reducing friction at the start of extrusion by a secondary lubricant. Theoretical estimation of unsteady extrusion pressure is in agreement for extrusion of aluminium billets lubricated with castor oil.

Pressure and Microstructural Change with Web to Flange Ratio and Die Land Length in Cold Extrusion of I-Shaped Lead Alloy

2009 ◽  
Vol 83-86 ◽  
pp. 7-15
Author(s):  
J.S. Ajiboye ◽  
S.A. Balogun ◽  
A.T. Agboola ◽  
G.J. Eke
Keyword(s):  
Plastic Deformation ◽  
Strain Rate ◽  
Deformation Process ◽  
Surface Hardness ◽  
Extrusion Pressure ◽  
Cold Extrusion ◽  
Lead Alloy ◽  
Fine Grained ◽  
Plastic Deformation Process ◽  
Superior Mechanical Properties

Plastic deformation process resulting in ultra fine grained materials which are rapidly grasping applications due to their superior mechanical properties remain an area of continued research interest. Generally, the influence of die land length and web to flange ratio in grain refinement subsequent to plastic deformation process have not being adequately exploited especially in complex die opening geometries. In the present study, the effect of these parameters on extrusion pressure and morphological change in I-shaped die opening geometry is investigated and reported. A forward extrusion rig is designed and manufactured for the purpose of experimental investigation. The upper bound analysis shows that increasing die land length leads to increasing relative extrusion pressure. Optimum web to flange ratio of 0.45 is numerically simulated and recommended to extrude I-shaped lead alloy with minimum load requirement. The experimental results reveal that increasing area ratio leads to quasi-sinusoidal pattern in surface hardness of I-shaped section irrespective of strain rate value. Increasing web to flange ratio, therefore, leads to increasing anisotropy of the I-shaped lead alloy. The extruded sections were examined with optical metallurgical microscope, and it is observed that increasing strain rate results in profound refinement of grain and inclusions in lead alloy even at room temperature.

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