On the Mechanics of Wire Drawing

1961 ◽  
Vol 83 (4) ◽  
pp. 523-529 ◽  
Author(s):  
C. T. Yang
Keyword(s):  
Theoretical Analysis ◽  
Shear Deformation ◽  
Coefficient Of Friction ◽  
Close Agreement ◽  
Wire Drawing ◽  
Experimental Results ◽  
Strain Gages ◽  
Drawing Force ◽  
The Coefficient Of Friction ◽  
Wire Resistance

Split-die technique was adopted to find the coefficient of friction in wire drawing directly from experiment. Simple dynamometers with wire resistance strain gages were used for measuring separating force and drawing force instead of cumbersome equipment used by former researchers. Reasonably good results were obtained. The effect of the land or parallel portion in the die on the coefficient of friction was indicated in the results. Its importance was emphasized. A theoretical equation of the drawing stress with the effect of land considered was derived. Using the coefficient of friction obtained by the split-die method, drawing stresses were calculated from the derived equation. A comparison of the theoretical and experimental drawing stresses was made. Results were tabulated and plotted. It was concluded that including the land in the analysis of wire drawing is important and further research in analyzing the shear deformation must be pursued in order to get a close agreement between theoretical analysis and experimental results.

Evaluation of drawing force by a new dimensionless method in deep drawing process

2020 ◽  
Vol 234 (13) ◽  
pp. 1604-1614
Author(s):  
Saeed Hajiahmadi ◽  
Majid Elyasi ◽  
Mohsen Shakeri
Keyword(s):  
Coefficient Of Friction ◽  
Deep Drawing ◽  
Experimental Tests ◽  
Geometric Parameters ◽  
Relational Model ◽  
Geometrical Parameters ◽  
Drawing Force ◽  
Dimensionless Parameters ◽  
Dimensionless Analysis ◽  
The Coefficient Of Friction

In this research, geometric parameters were given in dimensionless form by the Π- Buckingham dimensional analysis method in the dimensionless group for deep drawing of a round cup. To find the best group of dimensionless parameters and the fittest dimensionless relational model, three scales of the cup are evaluated numerically by a commercial finite element software and stepwise regression modeling. After analyzing all effective geometric parameters, a fittest relational model among dimensionless parameters is found. In addition, the results of the new dimensionless model were compared with the simulation process and experimental tests. From the results, it is inferred that the geometric qualities of a large scale can be predicted with a small scale by the proposed dimensionless model. Comparing the results of the dimensionless model with experimental tests shows that the proposed dimensionless model has fine precision in the determination of geometrical parameters and drawing force estimation. Moreover, to evaluate the accuracy of the proposed dimensionless model, the predicted value of the model has been compared by the experimental results. It is shown that the dimensionless ratios of geometrical parameters can significantly affect the estimation of the drawing force by the proposed dimensionless model, but based on similarity law, because of the constant value of these dimensionless parameters in different scales, they could not be used for dimensionless analysis separately. It is also inferred that because of the effect of contact area on the coefficient of friction, which is changed by scale changing, the only dimensionless parameter that can significantly change the drawing force is the coefficient of friction. Finally, it is shown that the dimensionless geometrical parameter and the coefficient friction should be combined for dimensionless analysis.

Study on the Friction and Wear Characteristics of Tungsten Carbide and Zirconium With Phosphor-Containing Liquid

2016 ◽  
Vol 139 (3) ◽  
Author(s):  
Myeong-Woo Ha ◽  
Kwang-Hee Lee ◽  
Chul-Hee Lee ◽  
Jong-Myung Choi ◽  
Jun-Wook An
Keyword(s):  
Tungsten Carbide ◽  
Coefficient Of Friction ◽  
Contact Surface ◽  
Friction And Wear ◽  
Yttrium Aluminum Garnet ◽  
Experimental Results ◽  
Wear Characteristics ◽  
Hard Materials ◽  
The Coefficient Of Friction ◽  
Friction And Wear Characteristics

The dispenser ejects the ceramic filler and phosphor-containing liquid for making various products. When the particle-containing liquid is ejected under high-velocity conditions, however, the ejection reliability decreases because of the wear of the contact surface between the rod and nozzle even though these components are made of hard materials. It is therefore necessary to characterize the friction and wear properties of the hard materials, tungsten carbide (WC) and zirconium (Zr), with the high-viscosity liquid-containing nitride or yttrium aluminum garnet (YAG) particles under reciprocating conditions. Particle contents of 15 wt.% and 30 wt.% are added to the liquid. A reciprocating test was implemented to this end, and WC and Zr specimens were used. The liquid used in the experiment contains nitride and YAG. The experimental results show that the particles inside the liquid are worn out, leading to particle lubrication and the decrease in the coefficient of friction. Also, it is confirmed that the more the particles are, the less the coefficient of friction is due to particle lubrication. For each experimental condition, the coefficient of friction is measured and compared. Moreover, the contact surface of the specimen is analyzed using an electron microscope, and a profilometer is used to measure the surface roughness of the specimen before and after the test. The reciprocation friction and wear characteristics of WC and Zr with phosphor-containing liquid are evaluated by analyzing the experimental results.

The Superposition of Longitudinal Sonic Oscillations on the Wire Drawing Process

1968 ◽  
Vol 183 (1) ◽  
pp. 545-562 ◽  
Author(s):  
C. E. Winsper ◽  
D. H. Sansome
Keyword(s):  
Experimental Data ◽  
Torsional Oscillation ◽  
Longitudinal Mode ◽  
Wire Drawing ◽  
Drawing Process ◽  
Drawing Force ◽  
The Coefficient Of Friction ◽  
The Wire ◽  
Oscillatory Energy ◽  
Good Agreement

Part 1: Characteristics of complete wire drawing apparatus Part 1 describes the wire drawing machine, instrumentation and oscillatory apparatus designed to establish the effects of applying oscillatory energy to the wire drawing process. A theoretical consideration of the vibration of the equipment is included and compared with experimental data. Tests were performed on a 3000 lbf bull-block and the oscillatory energy was supplied in a longitudinal mode from a 3000 lbf electro-hydraulic oscillator. Equipment was designed to measure drawing force, drawing torque, amplitude of die and drum oscillation, and drawing speed. Frequencies of die oscillation in the range 0–125 Hz were studied with amplitudes up to 0.070 in peak to peak. A study of process parameters, such as natural frequency of the system, damping of the bull-block drive, torsional oscillation of the drum, and die assembly inertia, showed that the analysis was in good agreement with experimental data and that it can be used to predict the effect of oscillations on the forces and torques acting during oscillatory wire drawing. Part 2 presents experimental data obtained from mild steel, hard aluminium, stainless steel and hard copper. Results show that there is no reduction in the peak drawing force and negligible reduction in the coefficient of friction. The results also confirm that oscillatory drawing is a mechanical process of straining and unstraining the drawn wire, and that the reduction in mean force can be determined by a mechanism of force superposition.

XXIII.—On the Cohesion of Steel, and on the Relation between the Yield Points in Tension and in Compression.

1908 ◽  
Vol 28 ◽  
pp. 374-381 ◽  
Author(s):  
G. H. Gulliver
Keyword(s):  
Mild Steel ◽  
Yield Point ◽  
Coefficient Of Friction ◽  
External Load ◽  
Frictional Resistance ◽  
Experimental Results ◽  
Cohesive Force ◽  
Metallic Particles ◽  
Resistance To Deformation ◽  
The Coefficient Of Friction

SUMMARY(a) On the assumptions that resistance to deformation is due to simple friction, and that the coefficient of friction is independent of the load, the ratio of the yield point in tension to the yield point in compression, for what is ordinarily known as mild steel, is calculated as 2·384 to 3·384, or as 0·705 to 1. Experimental results so far obtained do not agree well with these figures, the value for the tensile yield point being relatively high, and that for compression relatively low.(b) On the further assumption that a cohesive force acting between the metallic particles gives rise to a frictional resistance which may be added (algebraically) to that due to the effect of the external load, the value of this cohesive force is deduced as equal to 3·384 times the stress which corresponds with the tension yield point, or to 2·384 times that corresponding with the compression yield point. Experimental results from a large number of tests agree very fairly with the calculated figures for the case of tension.

Determining the Coefficient of Friction for Rolling Disks

1978 ◽  
Vol 100 (1) ◽  
pp. 25-30
Author(s):  
D. H. Offner ◽  
N. Tomita
Keyword(s):  
Potential Energy ◽  
Coefficient Of Friction ◽  
Surface Deformation ◽  
Empirical Relationship ◽  
Rolling Resistance ◽  
Experimental Results ◽  
Testing Device ◽  
The Coefficient Of Friction ◽  
Static Coefficient Of Friction ◽  
Static Coefficient

A method and testing device for determining a coefficient of friction for rolling disks is described. The method equates the energy of rolling resistance to the change in potential energy of a moving system. The experimental results of applying this method to steel, aluminum, and plexiglass disks of 3.8, 2.5, and 1.7 cm radii and 1 cm width rolling on steel and aluminum bases are summarized. An empirical relationship between the coefficient of friction and energy of surface deformation is presented. Use of device for determining the static coefficient of friction for impending rolling and sliding of disks is discussed.

A Method for Investigating the Coefficient of Friction in Tube Sinking through Conical Dies

1965 ◽  
Vol 7 (3) ◽  
pp. 279-282 ◽  
Author(s):  
G. G. Moore ◽  
J. F. Wallace
Keyword(s):  
Experimental Technique ◽  
Coefficient Of Friction ◽  
Experimental Results ◽  
The Coefficient Of Friction ◽  
Further Development ◽  
Continuous Determination

A theory, apparatus and experimental technique for the continuous determination of the coefficient of friction, μ, in tube sinking are briefly discussed and illustrated by some experimental results. The values of μ which have been obtained are lower than those usually accepted for evaluation of tube sinking theories. Suggestions are made for the further development of the technique.

Friction tests in tube hydroforming

2005 ◽  
Vol 219 (8) ◽  
pp. 587-593 ◽  
Author(s):  
Yeong-Maw Hwang ◽  
Li-Shan Huang
Keyword(s):  
Internal Pressure ◽  
Coefficient Of Friction ◽  
Tube Hydroforming ◽  
Test Method ◽  
Experimental Results ◽  
Friction Test ◽  
Friction Forces ◽  
Axial Feeding ◽  
The Coefficient Of Friction ◽  
Friction Test Method

The objective of this paper is to propose a friction test method to evaluate the performance of different kinds of lubricants and determine their coefficients of friction in tube hydroforming processes. A self-designed apparatus is used to conduct the experiments of friction tests. The coefficient of friction between the tube and the die at the guiding zone is determined. The effects of the internal pressure and the axial feeding velocity on the friction forces and coefficients of friction for various lubricants are discussed. From the experimental results, it is known that MoS2 corresponding to a coefficient of friction of 0.018 is the best lubricant among the evaluated lubricants during tube hydroforming processes.

Research Note: Average Friction Coefficients in Gears

1975 ◽  
Vol 17 (6) ◽  
pp. 360-362 ◽  
Author(s):  
A. C. Rao
Keyword(s):  
Coefficient Of Friction ◽  
Mathematical Analysis ◽  
Load Distribution ◽  
Power Loss ◽  
Experimental Results ◽  
Sliding Velocity ◽  
Friction Coefficients ◽  
Oil Film ◽  
Gear Teeth ◽  
The Coefficient Of Friction

Variation in sliding velocity—both in magnitude and direction—during a meshing cycle, the load distribution among the pairs of teeth, and the accuracy with which teeth are cut are some of the factors that make the mathematical analysis of friction in gear teeth extremely difficult. Of these, sliding velocity, which is responsible for the formation of an oil film between the teeth, plays an important role, and any attempt to determine the friction coefficients must take account of changes in sliding velocity. In this note an expression has been developed, considering the variation in sliding velocity, for power loss in terms of the coefficient of friction and gear parameters. The experimental results are compared with those obtained by other methods.

Measurement of Friction in Drawing, Extrusion, and Rolling

1968 ◽  
Vol 90 (1) ◽  
pp. 72-80 ◽  
Author(s):  
W. Evans ◽  
B. Avitzur
Keyword(s):  
Tool Wear ◽  
Coefficient Of Friction ◽  
Surface Finish ◽  
Wire Drawing ◽  
Flow Patterns ◽  
Complete Analysis ◽  
Experimental Procedure ◽  
The Coefficient Of Friction ◽  
Plastic Forming ◽  
Crucial Part

In the processes of plastic forming of metals, friction between the metal and the tools (dies) plays a crucial part. Forces, flow patterns, tool wear, and surface finish of the product as well as the capacity of the equipment (in rolling), all are affected by friction. A complete analysis of any process considers the coefficient of friction as a variable. A quantitative knowledge of the value of the coefficient of friction acting during processing is desired. This work proposes an experimental procedure for the evaluation of the coefficient of friction for processes like wire drawing and rod extrusion through an open die, for hydrostatic extrusion and for rolling.

scholarly journals A Semi-empirical Model of Air Waves Induced by Falling Rock in a Closed Goaf

2017 ◽  
Author(s):  
Fengyu Ren ◽  
Yang Liu ◽  
Jianli Cao ◽  
Rongxing He ◽  
Yuan Xu ◽  
...  
Keyword(s):  
Theoretical Analysis ◽  
Phase Velocity ◽  
Empirical Model ◽  
Close Agreement ◽  
Experimental Results ◽  
Uniform Motion ◽  
Protective Measures ◽  
Series Of Experiments ◽  
Semi Empirical ◽  
Wave Induced

In this paper, a semi-empirical model of air waves induced by falling rock is described. The model is composed of a uniform motion phase (velocity close to 0 m·s-1) and an acceleration movement phase. The uniform motion phase was determined based on experimentally and the acceleration movement phase was derived by theoretical analysis. A series of experiments were performed to verify the semi-empirical model and elucidated the law of the uniform motion phase. The acceleration movement phase accounted for a larger portion with a greater height of the falling rock. Experimental results of different falling heights of the goaf showed close agreement with theoretical analysis values. The semi-empirical model could accurately and conveniently estimate the velocity of air wave induced by falling rock. Thus, the semi-empirical model can provide a reference and basis for estimating the speed of air waves and designing protective measures in mines.

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