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.

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.

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.

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.

Mechanical strength improvement of aluminum foam-reinforced matrix for molten carbonate fuel cells

2017 ◽  
Vol 42 (25) ◽  
pp. 16235-16243 ◽  
Author(s):  
Mihui Lee ◽  
Chang-Whan Lee ◽  
Hyung-Chul Ham ◽  
Jonghee Han ◽  
Sung Pil Yoon ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Mechanical Strength ◽  
Aluminum Foam ◽  
Molten Carbonate ◽  
Molten Carbonate Fuel Cells ◽  
Strength Improvement

Preparation Techniques and Property Evaluations of Highly Air Permeable Needle-Punched Geotextiles

2015 ◽  
Vol 749 ◽  
pp. 278-281
Author(s):  
Jia Horng Lin ◽  
Jing Chzi Hsieh ◽  
Jin Mao Chen ◽  
Wen Hao Hsing ◽  
Hsueh Jen Tan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Service Life ◽  
Mechanical Strength ◽  
Pore Structure ◽  
Test Results ◽  
Needle Punching ◽  
Pet Fibers ◽  
Environmental Requirements ◽  
Preparation Techniques

Geotextiles are made of polymers, and their conjunction with different processes and materials can provide geotextiles with desirable characteristics and functions, such as filtration, separation, and drainage, and thereby meets the environmental requirements. Chemical resistant and mechanical strong polymers, including polyester (PET) and polypropylene (PP), are thus used to prolong the service life of the products made by such materials. This study proposes highly air permeable geotextiles that are made with different thicknesses and various needle punching speeds, and the influences of these two variables over the pore structure and mechanical properties are then examined. PET fibers, PP fibers, and recycled Kevlar fibers are blended, followed by being needle punched with differing spaces and speeds to form geotextiles with various thicknesses and porosities. The textiles are then evaluated for their mechanical strength and porosity. The test results show that a thickness of 4.5 cm and 1.5 cm demonstrate an influence on the tensile strength of the geotextiles, which is ascribed to the webs that are incompletely needle punched. However, the excessive needle punching speed corresponding to a thickness of 0.2 cm results in a decrease in tensile strength, but there is also an increase in the porosity of the geotextiles.

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.

scholarly journals Fundametal Characteristics of Zinc Phosphate Coating

1980 ◽  
Vol 66 (7) ◽  
pp. 924-934 ◽  
Author(s):  
Ryuji KOJIMA ◽  
Hiroshi OKITA ◽  
Yasunobu MATSUSHIMA
Keyword(s):  
Zinc Phosphate ◽  
Phosphate Coating
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