Development of Upsetting-Extrusion Type Tribometer for Evaluating Lubrication Coating Performance in Cold Forging

2013 ◽  
Vol 554-557 ◽  
pp. 833-843 ◽  
Author(s):  
Zhi Gang Wang ◽  
Shinobu Komiyama ◽  
Yasuharu Yoshikawa
Keyword(s):  
Zinc Phosphate ◽  
Side Surface ◽  
Extrusion Process ◽  
Peak Height ◽  
Expansion Ratio ◽  
Cold Forging ◽  
Maximum Height ◽  
Phosphate Coating ◽  
Free Expansion ◽  
Multi Stage

A new upsetting-extrusion type tribometer has been developed to investigate the performance of the lubrication coating on the side surface of a billet in the multi-stage cold forging. In this tribometer, the lubrication coating is first destroyed by the upsetting process due to the free expansion of the billet surface and then evaluated by the extrusion process. The frictional shear factor of the lubrication coating is obtained by plotting the measured extrusion load and the position after the extrusion of a centerline drawn on the billet in advance on the calibration curve obtained by FEM. Experimental results using a zinc phosphate coating and a dry in-place type coating showed that the reduced peak height Rpk is more appropriate than the maximum height Rz to express the effect of the surface roughness of tool on galling generation. When no galling occurs, the frictional shear factor hardly varies with the type of the lubrication coating and the surface expansion ratio. The anti-galling ability of the dry in-place type coating is greatly improved by a two-stage shot blast before the lubrication coating and reaches a level better than the zinc phosphate coating.

Development of Upsetting-Extrusion Type Tribometer for Evaluating Lubrication Coating Performance in Cold Forging

2014 ◽  
Vol 966-967 ◽  
pp. 281-289 ◽  
Author(s):  
Zhi Gang Wang ◽  
Shinobu Komiyama ◽  
Yasuharu Yoshikawa
Keyword(s):  
Zinc Phosphate ◽  
Side Surface ◽  
Extrusion Process ◽  
Peak Height ◽  
Expansion Ratio ◽  
Cold Forging ◽  
Maximum Height ◽  
Phosphate Coating ◽  
Multi Stage ◽  
Surface Expansion

A new upsetting-extrusion type tribometer is developed to investigate the performance of a lubrication coating on the side surface of a billet in multi-stage cold forging. In this tribometer, the lubrication coating on the billet surface is first destroyed by the upsetting process and then evaluated by the extrusion process. The frictional shear factor of the lubrication coating is obtained by plotting the measured extrusion load and the position after the extrusion of a centerline drawn on the billet in advance on the calibration curve obtained by FEM. Experimental results using a zinc phosphate coating and a dry in-place type coating showed that the reduced peak height Rpk is more appropriate than the maximum height Rz to express the effect of the surface roughness of tool on galling generation. When no galling occurs, the frictional shear factor hardly varies with the type of the lubrication coating and the surface expansion ratio. The anti-galling ability of the dry in-place type coating is greatly improved by a two-stage shot blast before the lubrication coating and reaches a level better than the zinc phosphate coating.

Seizure Strength Improvement for Phosphate-Stearate Coatings Involved in Cold Forging of Steel

1992 ◽  
Vol 114 (2) ◽  
pp. 248-252 ◽  
Author(s):  
Ph. Hivart ◽  
J. P. Bricout ◽  
J. Oudin ◽  
J. Y. Dauphin
Keyword(s):  
Mechanical Strength ◽  
Zinc Phosphate ◽  
Zinc Stearate ◽  
Cold Forging ◽  
Attractive Alternative ◽  
Phosphate Coating ◽  
Test Results ◽  
Phosphate Bonding ◽  
Strength Improvement ◽  
Tangential Friction

A seizure test particularly well suited to evaluate the mechanical strength of phosphate-stearate coatings has been developed. Test results, including tangential friction force and time at the onset of seizure, are related to the effective phosphate bonding and to lubricant reactive effects. It is shown that seizure is delayed if the phosphate coating is annealed at 500°C just before soaping. The γ-Zn3 (PO4)2 formation which occurs with a decrease in volume induces cracking along hopeite needles and causes an increase in reactive surface for soaping and, therefore, an increase in the quantity of zinc phosphate converted into zinc stearate. Improvement of the phosphate coating by annealing at 500°C before soaping may be an attractive alternative to the use of molybdenum disulfide lubricants.

Evaluation of lubricants without zinc phosphate precoat in multi-stage cold forging

CIRP Annals ◽  
2015 ◽  
Vol 64 (1) ◽  
pp. 285-288 ◽  
Author(s):  
Z.G. Wang ◽  
S. Komiyama ◽  
Y. Yoshikawa ◽  
T. Suzuki ◽  
K. Osakada
Keyword(s):  
Zinc Phosphate ◽  
Cold Forging ◽  
Multi Stage

Lubricating Performance of Residual Zinc Phosphate Coating on Forged Specimen in Bowden-Leben Sliding Test

2018 ◽  
Vol 767 ◽  
pp. 124-130 ◽  
Author(s):  
Osamu Kada ◽  
Zhi Gang Wang
Keyword(s):  
Surface Roughness ◽  
Friction Coefficient ◽  
Zinc Phosphate ◽  
Cold Forging ◽  
Phosphate Coating ◽  
Specimen Temperature ◽  
Tool Surface ◽  
Residual Thickness ◽  
Surface Expansion ◽  
Sliding Test

The lubricating performance of the zinc phosphate coating employed generally in cold forging is evaluated with Bowden-Leben sliding test by changing friction conditions such as the coating thickness, specimen temperature, the tool surface roughness, contact pressure and sliding speed. A specimen for the friction test is prepared from the inner surface of an extruded square cup and the residual thickness of the lubrication coating on the specimen is controlled by using the surface expansion in forward extrusion of the cup. Experimental results showed that the specimen temperature has the strongest influence on the friction coefficient. With an increase of the specimen temperature, the friction coefficient gradually decreases until 473K, and then increases sharply. With an increase of the tool surface roughness, the friction coefficient increases slightly. Friction coefficient is formulated as a function of the specimen temperature and the tool surface roughness. The anti-galling ability of the coating is affected by the residual thickness of lubrication coating, the specimen temperature and the tool surface roughness.

scholarly journals Multi-Stage Cold Forging Process for Manufacturing a High-Strength One-Body Input Shaft

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 532
Author(s):  
A Jo ◽  
Myeong Jeong ◽  
Sang Lee ◽  
Young Moon ◽  
Sun Hwang
Keyword(s):  
High Strength ◽  
Microstructural Characterization ◽  
Fatigue Tests ◽  
Machining Process ◽  
Cold Forging ◽  
Element Analysis ◽  
Forging Process ◽  
Input Shaft ◽  
Multi Stage ◽  
The One

A multi-stage cold forging process was developed and complemented with finite element analysis (FEA) to manufacture a high-strength one-body input shaft with a long length body and no separate parts. FEA showed that the one-body input shaft was manufactured without any defects or fractures. Experiments, such as tensile, hardness, torsion, and fatigue tests, and microstructural characterization, were performed to compare the properties of the input shaft produced by the proposed method with those produced using the machining process. The ultimate tensile strength showed a 50% increase and the torque showed a 100 Nm increase, confirming that the input shaft manufactured using the proposed process is superior to that processed using the machining process. Thus, this study provides a proof-of-concept for the design and development of a multi-stage cold forging process to manufacture a one-body input shaft with improved mechanical properties and material recovery rate.

scholarly journals Generalized optimizations of two-stage forging of micro/meso copper fastener

2018 ◽  
Vol 185 ◽  
pp. 00002
Author(s):  
Shih-Hsien Lin ◽  
Un-Chin Chai ◽  
Gow-Yi Tzou ◽  
Dyi-Cheng Chen
Keyword(s):  
Simulation Analysis ◽  
Effective Strain ◽  
Cold Forging ◽  
Two Stage ◽  
Forming Simulation ◽  
Multi Stage ◽  
Element Simulation ◽  
Die Stress ◽  
Stress Optimization ◽  
Forging Force

Three are generalized simulation optimizations considering the forging force, the die stress, and the dual-goals in two-stage forging of micro/meso copper fastener. Constant shear friction between the dies and workpiece is assumed to perform multi-stage cold forging forming simulation analysis, and the Taguchi method with the finite element simulation has been used for mold-and-dies parameters design simulation optimizations considering the forging force, die stress, and dual-goals. The die stress optimization is used to explore the effects on effective stress, effective strain, velocity field, die stress, forging force, and shape of product. The influence rank to forging process of micro/meso copper fastener for three optimizations can be determined, and the optimal parameters assembly consider die stress can be obtained in this study. It is noted that the punch design innovation can reduce the forging force and die stress.

Treatment of rinse water from zinc phosphate coating by batch and continuous electrocoagulation processes

2010 ◽  
Vol 173 (1-3) ◽  
pp. 326-334 ◽  
Author(s):  
M. Kobya ◽  
E. Demirbas ◽  
A. Dedeli ◽  
M.T. Sensoy
Keyword(s):  
Zinc Phosphate ◽  
Phosphate Coating ◽  
Rinse Water

Scorch Control of Carboxylic Elastomers

1973 ◽  
Vol 46 (1) ◽  
pp. 78-95 ◽  
Author(s):  
V. L. Hallenbeck
Keyword(s):  
Zinc Oxide ◽  
Physical Properties ◽  
Shelf Life ◽  
Zinc Sulfide ◽  
Zinc Phosphate ◽  
Carboxyl Groups ◽  
Carboxyl Group ◽  
Phosphate Coating ◽  
Ionic Bond ◽  
Cure Temperature

Abstract Carboxylic elastomers can be cured by standard compounding recipes utilizing sulfur and zinc oxide. The zinc oxide, besides aiding the sulfur cure, also gives a secondary cure through an ionic bond with the carboxyl groups. However, because of the affinity of the zinc oxide for the carboxyl group, the stocks tend to have an excessive scorch and a short shelf life. To prevent this excessive scorch the zinc oxide must be isolated from the carboxyl group until the desired cure temperature is reached. Three materials may be used to isolate the zinc oxide : 1) zinc sulfide coated zinc oxide, 2) zinc phosphate coated zinc oxide and 3) metallic alkoxide combined with the zinc oxide. The use of any of these gives scorch control without affecting final physical properties. The amount of zinc sulfide coating, zinc phosphate coating, and metallic alkoxide varies with the type of carboxylic elastomer.

Fließpressen hohler Wellen mit Wanddickenvariation/Cold forging of hollow shafts with wall thickness variation – Numerical investigation of a hollow forward extrusion process with adjustable deformation zone

2020 ◽  
Vol 110 (10) ◽  
pp. 684-688
Author(s):  
Alexander Weiß ◽  
Mathias Liewald
Keyword(s):  
Numerical Investigation ◽  
Metal Forming ◽  
Extrusion Process ◽  
Cold Forging ◽  
Thickness Variation ◽  
Part Geometry ◽  
Forming Technology ◽  
Wall Thickness Variation ◽  
The University ◽  
Hollow Shafts

Die Fertigung von Hohlwellen mit komplexer Innengeometrie bedingte bisher meist aufwendige Prozessrouten. Ein am Institut für Umformtechnik der Universität Stuttgart entwickeltes Kaltfließpressverfahren soll nun die wirtschaftliche und flexible Fertigung von Hohlwellen mit Wanddickenvariation ermöglichen. In diesem Beitrag werden das Verfahren beschrieben und die Ergebnisse der numerischen Untersuchung des Einflusses der Werkzeugkinematik auf die erzielbare Pressteilgeometrie dargelegt.   Usually, the production of hollow shafts with complex internal geometry by cold forging requires extensive process routes. A novel cold forging process developed at the Institute for Metal Forming Technology at the University of Stuttgart allows for an economical and flexible production of hollow shafts. This article describes the manufacturing process and presents the results of a numerical investigation for determining the influence of tool kinematics on the achievable part geometry.

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