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.

Coefficient of Friction for Aluminum Alloy Sheet in Contact with Polyurethane Rubber

2010 ◽  
Vol 26-28 ◽  
pp. 320-325 ◽  
Author(s):  
Li Li Wang ◽  
Dong Sheng Li ◽  
Xiao Qiang Li ◽  
Liang Wang ◽  
Wei Jun Yang
Keyword(s):  
Aluminum Alloy ◽  
Coefficient Of Friction ◽  
Normal Load ◽  
Orthogonal Experimental Design ◽  
Sliding Velocity ◽  
Stretch Forming ◽  
Forming Process ◽  
Alloy Material ◽  
The Coefficient Of Friction ◽  
The Impact

Stretch forming process of aircraft skin over reconfigurable compliant tooling is a new technology in skin manufacturing. During this process, the coefficient of friction is important for modeling accurately the process of stretch forming. The objective of this research is to measure the coefficient of friction for aluminum alloy in contact with polyurethane rubber in reciprocal sliding. An orthogonal experimental design was used to reveal the impact of four factors on the coefficient of friction, including lubrication, normal load, aluminum alloy material and sliding velocity. It is shown that lubrication is a major factor, sliding velocity is a minor factor. The influence of normal pressure is less than sliding velocity and the influence of aluminum alloy material is not very obvious. Finally, based on the experiment results, the selections of lubricant and stretching velocity are discussed in order to improve the process of stretch forming.

The Results Comparasion of Calculation Method and Computer Modeling of Double Curvature Sheet Shells in Stretch Forming Process

2016 ◽  
Vol 684 ◽  
pp. 21-28 ◽  
Author(s):  
V.A. Mikheev ◽  
S.V. Surudin
Keyword(s):  
Computer Simulation ◽  
Key Words ◽  
Calculation Method ◽  
Stretch Forming ◽  
Forming Process ◽  
Double Curvature ◽  
Formation Stage ◽  
Straight Line ◽  
The Press ◽  
Simulation Results

In this paper was conducted the dichotomous principle analysis, which based on the results comparability of calculation method and the computer simulation results of forming double curvature sheet shells using new scheme stretch forming and program PAM-stamp. The new scheme involves initially perform shaping the central part of the shell with the press jaws of the straight line. Then press clips installed on the contours, which corresponding with curves of stretch die end sections, and performed extension stretch forming up to a point. The results of the calculation method allows to compare the formation stage and extension stretch forming on the results of computer simulation and quickly find the practical applicability of the new scheme extension stretch forming on modern stretch forming press such as FEL. Key words: extension stretch forming process, double curvature shell, computer simulation results, calculation method, stretch forming press FEL.

Performance characteristics of modified antifriction coatings based on the metal composition

2020 ◽  
pp. 186-194
Author(s):  
Aleksey G. Ipatov ◽  
Sergey N. Shmykov
Keyword(s):  
Laser Treatment ◽  
Pulse Laser ◽  
Coefficient Of Friction ◽  
Short Pulse ◽  
Boundary Friction ◽  
Research Purpose ◽  
X Ray ◽  
Short Pulse Laser ◽  
Antifriction Coatings ◽  
The Coefficient Of Friction

This paper proposes the technology for obtaining antifriction coatings by short-pulse laser treatment of powder compositions. (Research purpose) The research purpose is in synthesizing thin anti-friction coatings on the surface of steel substrates by short-pulse laser treatment of metal powder compositions and analyze their physical and mechanical properties. (Materials and methods) A solid-state pulsed laser generator was used to synthesize antifriction coatings. B83 babbit powder has been used as an additive material. The powder composition was additionally doped with PMS-1 copper and molybdenum disulfide in order to increase the friction properties and load-bearing capacity of the coatings. Laboratory samples were subjected to wear tests under boundary friction conditions using the SMT-2070 friction machine in comparison with standard surfaces of B83 babbite coating, steel surface, and Molykote d-321R clad surface. X-ray diffractometer DRON-6 was used for x-ray diffractometry. (Results and discussion) It was found that the porosity of the modified coating does not exceed 5 percent, and there are no traces of detachment and destruction in the experimental samples. It was found that the coefficient of friction of the analyzed coating under conditions of boundary friction was 0.12-0.13, which corresponds to the coefficient of friction of a standard babbit alloy. The modified coating have a more efficient workability and a stable coefficient of friction over a large range of loads. It was found that the wear intensity of the analyzed coating is significantly lower than one of the compared surfaces. The increase in friction characteristics is due to the features of the coating structure, which is characterized by a large number of solid intermetallic compounds Cu3Sn having a hexagonal structure, which determines the low friction coefficient. (Conclusions) The results shows the high practical potential of modified antifriction coatings that can be used in mechanical engineering and repair production in the design and restoration of bearing assemblies.

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.

Numerical Simulation of High Inner-Pressure Hydroforming of T-Branch Tube

2011 ◽  
Vol 194-196 ◽  
pp. 2193-2198
Author(s):  
Liang Chu ◽  
Jian Zhang ◽  
Da Sen Bi
Keyword(s):  
Internal Pressure ◽  
Coefficient Of Friction ◽  
Feed Rate ◽  
Tube Hydroforming ◽  
Simulation Software ◽  
Extrusion Force ◽  
Forming Process ◽  
Forming Quality ◽  
Inner Pressure ◽  
The Coefficient Of Friction

The paper studies the forming process of high inner-pressure hydroforming of T-branch tube by using DYNAFORM finite element simulation software based on its technology characteristics. First, the effects of different loading paths of key parameters(internal pressure, axial extrusion force, radial back force) on T-branch tube hydroforming process have been studied. The studies show that enough feed rate is essential to obtaining a certain branch height but excess feed rate can lead to the thickness seriously increased. The way of influence of internal pressure is contrary to radial back force, both excess internal pressure and slight radial back force can cause top branch thinned or fractured. If branch height is too low, radial back force will obstruct the extension of tube and productions cannot be compliance with design requirements. Second, the effects of coefficient of friction and radius of round angles on forming quality of T-branch tube have been discussed. The studies show that forming quality is better when the coefficient of friction is smaller or radius of round angles is larger.

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.

Experimental Investigation of aluminum doping crumb rubber/epoxy composite in reciprocating motion

2015 ◽  
Vol 3 ◽  
pp. 1
Author(s):  
Goutam Chandra Karar ◽  
Nipu Modak
Keyword(s):  
Experimental Investigation ◽  
Coefficient Of Friction ◽  
Epoxy Composite ◽  
Normal Load ◽  
Crumb Rubber ◽  
The Other ◽  
Reciprocating Motion ◽  
Molding Process ◽  
Friction Tester ◽  
The Coefficient Of Friction

The experimental investigation of reciprocating motion between the aluminum doped crumb rubber /epoxy composite and the steel ball has been carried out under Reciprocating Friction Tester, TR-282 to study the wear and coefficient of frictions using different normal loads (0.4Kg, 0.7Kgand1Kg), differentfrequencies (10Hz, 25Hz and 40Hz).The wear is a function of normal load, reciprocating frequency, reciprocating duration and the composition of the material. The percentage of aluminum presents in the composite changesbut the other components remain the same.The four types of composites are fabricated by compression molding process having 0%, 10%, 20% and 30% Al. The effect of different parameters such as normal load, reciprocating frequency and percentage of aluminum has been studied. It is observed that the wear and coefficient of friction is influenced by the parameters. The tendency of wear goes on decreasing with the increase of normal load and it is minimum for a composite having 10%aluminum at a normal load of 0.7Kg and then goes on increasing at higher loads for all types of composite due to the adhesive nature of the composite. The coefficient of friction goes on decreasing with increasing normal loads due to the formation of thin film as an effect of heat generation with normal load.

scholarly journals Tribological Aspects, Optimization and Analysis of Cu-B-CrC Composites Fabricated by Powder Metallurgy

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4217
Author(s):  
Üsame Ali Usca ◽  
Mahir Uzun ◽  
Mustafa Kuntoğlu ◽  
Serhat Şap ◽  
Khaled Giasin ◽  
...  
Keyword(s):  
Weight Loss ◽  
Wear Rate ◽  
Coefficient Of Friction ◽  
Applied Load ◽  
Practical Significance ◽  
Tribological Characteristics ◽  
M 10 ◽  
Wide Range ◽  
The Coefficient Of Friction ◽  
Four Levels

Tribological properties of engineering components are a key issue due to their effect on the operational performance factors such as wear, surface characteristics, service life and in situ behavior. Thus, for better component quality, process parameters have major importance, especially for metal matrix composites (MMCs), which are a special class of materials used in a wide range of engineering applications including but not limited to structural, automotive and aeronautics. This paper deals with the tribological behavior of Cu-B-CrC composites (Cu-main matrix, B-CrC-reinforcement by 0, 2.5, 5 and 7.5 wt.%). The tribological characteristics investigated in this study are the coefficient of friction, wear rate and weight loss. For this purpose, four levels of sliding distance (1000, 1500, 2000 and 2500 m) and four levels of applied load (10, 15, 20 and 25 N) were used. In addition, two levels of sliding velocity (1 and 1.5 m/s), two levels of sintering time (1 and 2 h) and two sintering temperatures (1000 and 1050 °C) were used. Taguchi’s L16 orthogonal array was used to statistically analyze the aforementioned input parameters and to determine their best levels which give the desired values for the analyzed tribological characteristics. The results were analyzed by statistical analysis, optimization and 3D surface plots. Accordingly, it was determined that the most effective factor for wear rate, weight loss and friction coefficients is the contribution rate. According to signal-to-noise ratios, optimum solutions can be sorted as: the highest levels of parameters except for applied load and reinforcement ratio (2500 m, 10 N, 1.5 m/s, 2 h, 1050 °C and 0 wt.%) for wear rate, certain levels of all parameters (1000 m, 10 N, 1.5 m/s, 2 h, 1050 °C and 2.5 wt.%) for weight loss and 1000 m, 15 N, 1 m/s, 1 h, 1000 °C and 0 wt.% for the coefficient of friction. The comprehensive analysis of findings has practical significance and provides valuable information for a composite material from the production phase to the actual working conditions.

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