scholarly journals Research of tribotechnical characteristics of materials used in the development of compositions of lubricants for casting under pressure of aluminum alloys and polymeric products

2020 ◽  
pp. 110-115
Author(s):  
A. M. Mikhaltsov ◽  
A. A. Skaskevich ◽  
Ya. I. Tsishkova
Keyword(s):  
Aluminum Alloys ◽  
Injection Molding ◽  
Coefficient Of Friction ◽  
Soap Stock ◽  
Polymeric Materials ◽  
Petroleum Jelly ◽  
Steel Disk ◽  
The Coefficient Of Friction ◽  
Materials Used ◽  
Tribotechnical Characteristics

The article describes the requirements for lubricants (release coatings) used in injection molding of aluminum alloys and polymeric materials. A methodology for conducting research to determine the tribotechnical characteristics of materials used in the development of the composition of a lubricant for injection molding aluminum alloys and polymer products, as well as the results of a study of tribotechnical characteristics (friction coefficient) are presented. It has been established that as materials used in the development of a multifunctional lubricant composition for casting aluminum alloys and polymer products, it is advisable to use a fraction of soap stock and fus after their preliminary sedimentation (at least 3 months). It is shown that the smallest value of the coefficient of friction at the time of indenter breaking on the surface of the steel disk was obtained using a fus. Moreover, the value of the coefficient of friction is 14–33% lower than the same indicator for other studied lubricants (petroleum jelly, PMS-100 and soap stock). It was found that in the mode of reciprocal movement of the indenter on the surface of the steel disk, the coefficient of friction when using a fus is 1,7–3,3 times lower than when using Vaseline, PMS-100 and soap stock as lubricant.

THE INFLUENCE OF REDUCING TEMPERATURE ON CHANGING YOUNG’S MODULUS AND THE COEFFICIENT OF FRICTION OF SELECTED SLIDING POLYMERS

Tribologia ◽  
2018 ◽  
Vol 279 (3) ◽  
pp. 107-111
Author(s):  
Anita PTAK ◽  
Piotr KOWALEWSKI
Keyword(s):  
Friction Coefficient ◽  
Young’S Modulus ◽  
Coefficient Of Friction ◽  
Tribological Properties ◽  
Young's Modulus ◽  
Polymeric Materials ◽  
Kinetic Friction ◽  
Mechanical And Tribological Properties ◽  
Pin On Disc ◽  
The Coefficient Of Friction

For the polymeric materials, changing of the temperature causes changes in mechanical and tribological properties of sliding pairs. The goal of the present study was to determine the change in Young's modulus and kinetic friction coefficient depending of the temperature. Three thermoplastic polymers, PA6, PET and PEEK, were tested. These materials cooperated in sliding motion with a C45 construction steel disc. As part of the experiment, the Young's modulus tests (by 3-point bending method) and kinetic friction coefficient studies (using pin-on-disc stand) were carried out. The temperature range of mechanical and tribological tests was determined at T = –50°C±20°C. Comparing the results of mechanical and tribological properties, there is a tendency to decrease the coefficient of friction as the Young's modulus increases while reducing the working temperature.

Tribological Behavior of Polymer Seal Materials in Water-Based Hydraulic Fluids

2018 ◽  
Vol 140 (6) ◽  
Author(s):  
S. Bernat ◽  
A. Brink ◽  
M. Lucas ◽  
N. Espallargas
Keyword(s):  
Water Content ◽  
Coefficient Of Friction ◽  
Polymer Materials ◽  
Elastic Behavior ◽  
Hydraulic Fluid ◽  
Steady Growth ◽  
Hydraulic Fluids ◽  
Water Based ◽  
The Coefficient Of Friction ◽  
Materials Used

In this work, two polymer materials have been tested in a lubricated reciprocating pin-on-plate contact geometry using water-based hydraulic fluids to simulate sliding conditions of seal materials used in offshore equipment. The effect of load, speed, water content of the lubricant, and soaking of the ultra-high molecular weight polyethylene (UHMWPE) and a polyketone (PK) sliding against a super-duplex stainless steel (SDSS) was studied. The results showed that for UHMWPE, an increase in normal force leads to a decrease in coefficient of friction for all velocities. While under the same sliding conditions, no relevant influence of load on friction coefficient was found for PK. On the other hand, an increase in sliding speed decreased the coefficient of friction for both materials. The effect of the water content of the hydraulic fluid on the tribological performance was also studied. In UHMWPE-SDSS system, increasing water content in the hydraulic fluid resulted in steady growth of the transfer film. One reason for this might be the decreasing lubricant viscosity, which moves the system toward the boundary lubrication regime. In addition, it was found that the incubation of both UHMWPE and PK in water-based lubricants showed a beneficial effect on friction and wear, which was explained by the change in polymer visco-elastic behavior.

THE EFFECT OF THE COEFFICIENT OF FRICTION ON THE BIOMECHANICS OF CONTACT IN HIP ENDOPROSTHESIS

Tribologia ◽  
2017 ◽  
Vol 273 (3) ◽  
pp. 137-146
Author(s):  
Anna M. RYNIEWICZ ◽  
Tomasz MADEJ ◽  
Wojciech RYNIEWICZ ◽  
Łukasz BOJKO ◽  
Mieczysław CHOROMAŃSKI
Keyword(s):  
Wear Resistance ◽  
Coefficient Of Friction ◽  
Hip Joints ◽  
Hip Endoprosthesis ◽  
Replacement Surgery ◽  
Hip Replacement Surgery ◽  
The Coefficient Of Friction ◽  
Materials Used ◽  
Two Parameters ◽  
Selection Of

Hip replacement surgery, by introducing a specific replacement head on the stem and cup, completely changes the conditions of co-operation typical for the biological correct pair. The clinical selection of endoprosthesis, apart from other conditionings, involves a dilemma between the choice of a rigid tribological node and the selection of a susceptible bearing cushioning the locomotive loads. The aim of the study is to evaluate the coefficient of friction and wear resistance of materials used for sliding contact in the endoprostheses of hip joints. On the basis of the conducted tests, it can be stated that, in the selection of material for cups of endoprosthesis, the wear resistance is important, and the coefficient of friction in contact head and cup in the prosthesis is less important. The presence of significant disproportions between the two parameters of the tribological process proves that the biomaterial is less useful on the cup. In the assessment of cooperation in the endoprosthesis, simulations of the contact of structural elements are useful, because, on that basis, in the correlation with tribological parameters, one can make conclusions about the distribution of stresses and displacements that may determine the lifetime of the implant.

An Empirical Model for the Coefficient of Friction in Injection Molding of Thermoplastics

2013 ◽  
Author(s):  
Omar Bataineh
Keyword(s):  
Injection Molding ◽  
Coefficient Of Friction ◽  
Empirical Model ◽  
Complex Task ◽  
Roughness Effect ◽  
Friction Forces ◽  
The Coefficient Of Friction ◽  
Ejector System ◽  
Contact Surfaces ◽  
Adhesion Effect

Predicting friction forces present between part and mold surfaces in injection molding of thermoplastics is considered an important step in the design of the ejector system. However, this requires calculating the coefficient of friction at the contact surfaces, which is usually a complex task. In this study, an empirical model is developed in an attempt to estimate the coefficient of friction as applicable for the injection molding of thermoplastics. It is assumed in this model that the coefficient of friction is a sum of two correlated effects: adhesion effect and surface roughness effect. Both effects are treated as functions of mold surface’s average asperity slope.

scholarly journals APPLICATION OF ANTIFRICTION COATINGS TO REDUCE CONTACT FRICTION IN STRETCH-FORMING PROCESS OF DOUBLE CURVATURE SHELLS ON A DIES MADE OF ALUMINUM ALLOYS

2021 ◽  
Vol 23 (1) ◽  
pp. 41-47
Author(s):  
G.L. Rivin ◽  
◽  
E.G. Karpukhin ◽  
A.O. Koshkina ◽  
◽  
...  
Keyword(s):  
Aluminum Alloys ◽  
Coefficient Of Friction ◽  
Contact Friction ◽  
Technological Properties ◽  
Stretch Forming ◽  
Forming Process ◽  
Properties Of Coatings ◽  
Double Curvature ◽  
Antifriction Coatings ◽  
The Coefficient Of Friction

The article presents the results of research on antifriction coatings for use on die made of aluminum alloys. The expediency of using antifriction coatings to reduce friction when stretch-forming of double curvature shells is justified. To substantiate this, we performed numerical modeling of the skin-tight forming process in the «LS-dyna» CAE system. According to the results of modeling, the following relationship is observed: the lower the coefficient of friction, the more evenly distributed the thinning deformations over the thickness of the blank in stretch-forming. Test modes for determining the coefficient of friction on the MTU-01 friction machine and methods for obtaining other basic functional and technological properties of antifriction coatings are described. The antifriction and technological properties of coatings, such as the coefficient of friction, adhesion, wear resistance, conditional hardness, the time and temperature of polymerization of the coating are determined.

scholarly journals STRUCTURE AND PROPERTIES OF THE АК12М2МгН (AlSi12Cu2MgNi) PISTON ALLOY FORMED UNDER THE INFLUENCE OF A COMPLEX MODIFYING ADDITIVE OF FULLERENE-CONTAINING SOOT AND COPPER

2021 ◽  
Vol 2 (55) ◽  
pp. 73-80
Author(s):  
A.I. Komarov ◽  
◽  
D.V. Orda ◽  
D.O. Iskandarova ◽  
◽  
...  
Keyword(s):  
Coefficient Of Friction ◽  
Relative Elongation ◽  
High Wear Resistance ◽  
Simultaneous Increase ◽  
Structure And Properties ◽  
Carbon Particles ◽  
Study Results ◽  
The Coefficient Of Friction ◽  
Tribotechnical Characteristics ◽  
Modifying Additive

The article presents the study results of the complex modification of eutectic silumin АК12М2МгН (AlSi12Cu2MgNi) with additives of fullerene-containing soot (FCS) and copper. It is shown that the effect on the alloy structure is caused by the introduction of carbon nanoparticles into the melt and is manifested in the dispersion of the structural phases and their uniform distribution in the casting volume. At the same time, the use of dispersed copper powder provides wetting of aluminum carbon particles with the melt and additional alloying of the melt. The formation of a dispersed structure leads to an increase in the mechanical and tribotechnical characteristics of the alloy: an increase in the ultimate strength (by 1.3–1.6 times) with a simultaneous increase in the relative elongation by up to 3 times, a significant decrease in the coefficient of friction (by 1.1–1.7 times) and the intensity of wear. The lowest coefficient of friction and high wear resistance are achieved at small fractions of FCS (0.05–0.1 wt.%) and the copper content in the modifier is not more than 0.5 wt.%.

Study of Friction in Cold Strip Rolling

1984 ◽  
Vol 106 (2) ◽  
pp. 139-146 ◽  
Author(s):  
Lim Lai-Seng ◽  
J. G. Lenard
Keyword(s):  
Aluminum Alloys ◽  
Coefficient Of Friction ◽  
Strip Rolling ◽  
Roll Pressure ◽  
Average Coefficient ◽  
The Coefficient Of Friction ◽  
Frictional Coefficients ◽  
Roll Gap ◽  
Cold Strip Rolling

Experiments were conducted to measure the effects of roll pressure and roll rpm on the magnitude and variation of the coefficient of friction in the roll gap in cold strip rolling. Two aluminum alloys (1100-T0 and 5052-H34) were used in the experiments. Roll pressures were found not to affect the frictional coefficients in a significant manner. Speed of rolling was identified as the most important parameter as far as the values of μ are concerned. Increased speeds appeared to lower the values of the average coefficient of friction.

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