Analysis of Wire Drawing and Extrusion Through Conical Dies of Small Cone Angle

1963 ◽  
Vol 85 (1) ◽  
pp. 89-95 ◽  
Author(s):  
Betzalel Avitzur
Keyword(s):  
Cone Angle ◽  
Wire Drawing ◽  
Power Balance ◽  
Wire Radius ◽  
Process Variables ◽  
Power Losses ◽  
Uniaxial Load ◽  
The Wire ◽  
Analytical Expressions ◽  
Entrance Velocity

Analytical expressions are derived for the required front pull for wire drawing, as well as the back push for extrusion. The effect of each of the process variables on these forces is presented graphically. The process variables are: the cone’s semiangle (α) initial (Ri) and final (Rf) wire radius, material yield limit (σ0) at uniaxial load, back pull (σxb) and front pull (σxf), coefficient of friction (μ) or shear factor (m), die land (L), exit velocity (vf), and entrance velocity (vi). The power balance is set for these powers: (1) Internal power of deformation of the wire, (2) power involved with the back force on the wire, (3) power involved with the front force on the wire, (4) power losses due to friction between the wire and the die.

Analysis of Wire Drawing and Extrusion Through Conical Dies of Large Cone Angle

1964 ◽  
Vol 86 (4) ◽  
pp. 305-314 ◽  
Author(s):  
Betzalel Avitzur
Keyword(s):  
Cone Angle ◽  
Wire Drawing ◽  
Wire Radius ◽  
Yield Limit ◽  
Process Variables ◽  
Absolute Value ◽  
Direct Extension ◽  
Yield Value ◽  
Half Angle ◽  
Large Cone Angle

This work is a direct extension of reference [3]. There the problem was treated with the assumption that the cone angle was small. Here this limitation exists no more. The operations of wire drawing and extrusion through conical dies are treated on the assumption that “Mises” material is formed. An upper-bound solution is obtained for the drawing stress in wire drawing and for the pushing stress in extrusion. The effect of each of the process variables on these forces is presented graphically. The process variables are: the cone half-angle (α), initial (Ri) and final (Rf) wire radius, material yield limit (σ0) under uniaxial load, back pull (σxb) and front pull (σxf), coefficient of friction (μ) or shear factor (m), die land (L), exit velocity (vf), and entrance velocity (vi). On the assumption that the maximum front tension cannot exceed the yield limit of the material under uniaxial tension, a solution is obtained for maximum possible reduction in wire drawing. An analogous assumption, i.e., that the absolute value of the pushing stress also cannot exceed the yield value, gives a criterion for maximum possible reduction in extrusion.

Influence of the Die Bearing Length on the Hydrogen Embrittlement of Cold Drawn Wires

2013 ◽  
Vol 577-578 ◽  
pp. 553-556 ◽  
Author(s):  
Jesús Toribio ◽  
Miguel Lorenzo ◽  
L. Aguado ◽  
Diego Vergara ◽  
Viktor Kharin
Keyword(s):  
Hydrogen Embrittlement ◽  
Hydrogen Diffusion ◽  
Cold Drawing ◽  
Wire Drawing ◽  
Wire Radius ◽  
Drawing Process ◽  
Strain Fields ◽  
Characteristic Value ◽  
The Wire ◽  
Definition Of

Prestressing steels, obtained by cold drawing, are highly susceptible to hydrogen embrittlement (HE) phenomena. Stress and strain fields produced by cold drawing play an essential role in this process since they affect hydrogen diffusion. Therefore, variations of such fields due to changes in drawing conditions could modify life in-service of these structural components. In this work the effect on HE of a parameter of the wire drawing process, thebearing length, is analyzed by means of diverse numerical simulations by the finite element method (FEM). The results of this work allow the definition of acharacteristic valueof the die bearing length equal to the wire radius, and demonstrate that the effects of stress-strain fields produced by wire drawing on HE are reduced when the bearing length exceeds such a characteristic value, so that the optimum cold drawing process is that with a bearing length higher than the wire radius.

Microstructural Development in Nb-Ti Multifilamentary Superconductors During Processing

1985 ◽  
Vol 43 ◽  
pp. 190-191
Author(s):  
A. W. West
Keyword(s):  
Heat Treatment ◽  
Critical Current Density ◽  
Copper Matrix ◽  
Wire Drawing ◽  
Heat Treatments ◽  
Microstructural Development ◽  
Final Size ◽  
Density Values ◽  
The Wire ◽  
Multifilamentary Superconductors

The influence of the filament microstructure on the critical current density values, Jc, of Nb-Ti multifilamentary superconducting composites has been well documented. However the development of these microstructures during composite processing is still under investigation.During manufacture, the multifilamentary composite is given several heat treatments interspersed in the wire-drawing schedule. Typically, these heat treatments are for 5 to 80 hours at temperatures between 523 and 573K. A short heat treatment of approximately 3 hours at 573K is usually given to the wire at final size. Originally this heat treatment was given to soften the copper matrix, but recent work has shown that it can markedly change both the Jc value and microstructure of the composite.

Benefits of Using Diamond Dies for Cold Alternate Drawing of Magnesium Alloys

2016 ◽  
Vol 716 ◽  
pp. 13-21 ◽  
Author(s):  
Vladimir Stefanov Hristov ◽  
Kazunari Yoshida
Keyword(s):  
Magnesium Alloy ◽  
Weight Ratio ◽  
High Strength ◽  
Wire Drawing ◽  
High Ductility ◽  
Element Analysis ◽  
The Wire ◽  
Shearing Strain ◽  
Drawing Method

In recent years, due to its low density and high strength/weight ratio, magnesium alloy wires has been considered for application in many fields, such as welding, electronics, medical field (for production of stents). But for those purposes, we need to acquire wires with high strength and ductility. For that we purpose we proposed alternate drawing method, which is supposed to highly decrease the shearing strain near the surface of the wire after drawing, by changing the direction of the wire drawing with each pass and thus acquiring high ductility wires.We have done research on the cold alternate drawing of magnesium alloy wires, by conducting wire drawing of several magnesium wires and testing their strength, hardness, structure, surface and also finite element analysis, we have proven the increase of ductility at the expense of some strength.In this research we are looking to further improve the quality of the drawn wires by examining the benefits of using diamond dies over tungsten carbine dies. Using the alternate drawing method reduces the strength of the drawn wires and thus lowering their drawing limit. By using diamond dies we are aiming to decrease the drawing stress and further increase the drawing limit of the alternate drawn wires and also improve the quality of the finishing surface of the wires. With this in mind we are aiming to produce a good quality wire with low diameter, high ductility, high strength and fine wire surface.

Research on the Wire Drawing Die Pass Parameter Calculation Based on the Least Square Algorithm

2012 ◽  
Vol 591-593 ◽  
pp. 850-853
Author(s):  
Huai Xing Wen ◽  
Yong Tao Yang
Keyword(s):  
Pore Structure ◽  
Least Squares ◽  
Least Squares Method ◽  
Piecewise Linear ◽  
Wire Drawing ◽  
Least Square ◽  
Structure Characteristics ◽  
Drawing Die ◽  
The Wire ◽  
Drawing Dies

Drawing Dies meter A / D acquisition module will be collected from the mold hole contour data to draw a curve in Matlab. According to the mold pore structure characteristics of the curve, the initial cut-off point of each part of contour is determined and iteratived optimization to find the best cut-off point, use the least squares method for fitting piecewise linear and fitting optimization to find the function of the various parts of the curve function, finally calculate the pass parameters of drawing mode. Parameters obtained compare with the standard mold, both of errors are relatively small that prove the correctness of the algorithm. Also a complete algorithm flow of pass parameters is designed, it can fast and accurately measure the wire drawing die hole parameters.

Analytical Model of the Efficiency of Spur Gears: Study of the Influence of the Design Parameters

2011 ◽  
Author(s):  
Miguel Pleguezuelos ◽  
Jose´ I. Pedrero ◽  
Miryam B. Sa´nchez
Keyword(s):  
Load Distribution ◽  
Gear Ratio ◽  
Design Parameters ◽  
Spur Gears ◽  
Transmitted Power ◽  
Power Losses ◽  
Contact Ratio ◽  
Complete Study ◽  
Uniform Model ◽  
Analytical Expressions

An analytic model to compute the efficiency of spur gears has been developed. It is based on the application of a non-uniform model of load distribution obtained from the minimum elastic potential criterion and a simplified non-uniform model of the friction coefficient along the path of contact. Both conventional and high transverse contact ratio spur gears have been considered. Analytical expressions for the power losses due to friction, for the transmitted power and for the efficiency are presented. From this model, a complete study of the influence of some design parameters (as the number of teeth, the gear ratio, the pressure angle, the addendum modification coefficient, etc.) on the efficiency is presented.

Deformation Law of Cold Drawing Process of High Strength Bridge Cable Steel

2021 ◽  
Vol 1035 ◽  
pp. 801-807
Author(s):  
Xiao Lei Yin ◽  
Jian Cheng ◽  
Gang Zhao
Keyword(s):  
Strain Path ◽  
High Strength ◽  
Cold Drawing ◽  
Wire Drawing ◽  
Radial Deformation ◽  
Steel Bridge ◽  
Drawing Process ◽  
Single Pass ◽  
Potential Relationship ◽  
The Wire

High-strength cable-steel bridge is the “lifeline” of steel structure bridges, which requires high comprehensive mechanical properties, and cold-drawing is the most important process to produce high-strength cable-steel bridge. Therefore, through the ABAQUS platform, a bridge wire drawing model was established, and the simulation analysis on the process of stress strain law and strain path trends for high-strength bridge steel wire from Φ 12.65 mm by seven cold-drawing to Φ 6.90 mm was conducted. The simulation results show that the wire drawing the heart of the main axial deformation, surface and sub-surface of the main axial and radial deformation occurred, with the increase in the number of drawing the road, the overall deformation of the wire was also more obvious non-uniformity. In the single-pass drawing process, the change in the potential relationship of each layer of material was small, and multiple inflection points appeared in the strain path diagram; the change in the seven-pass potential relationship was more drastic, which can basically be regarded as a simple superposition of multiple single-pass pulls.

scholarly journals Input Admittance, Directivity and Quality Factor of Biconical Antenna of Arbitrary Cone Angle

2021 ◽  
Author(s):  
Ramakrishna Janaswamy
Keyword(s):  
Quality Factor ◽  
Cone Angle ◽  
Analytical Formula ◽  
Wide Angle ◽  
Slowly Varying Function ◽  
Input Admittance ◽  
Arbitrary Length ◽  
Biconical Antenna ◽  
Arbitrary Cone ◽  
Analytical Expressions

New analytical expressions and numerical results for the quality factor and directivity as well as computationally convenient expressions for the input admittance of a symmetrical biconical antenna of arbitrary length $L$ and cone angle $\theta_0$ are presented. The quality factor for a wide-angle biconical antenna is shown to very closely approach the Chu's limit of $Q = (kL)^{-1}\{1+(kL)^{-2}\}$. Numerical calculations based on the analytical formula for antenna admittance confirm the conjecture that Foster's reactance theorem remains invalid even for perfectly conducting antennas. Furthermore, the variation of directivity of a wide-angle biconical antenna is a slowly varying function of its electrical length and is shown to depart significantly from that of a thin cylindrical dipole. <br>

Modeling of Geometry Design in Wire Drawing Using Cassette Roller Die

2007 ◽  
Vol 23 ◽  
pp. 173-176 ◽  
Author(s):  
Liviu Nistor ◽  
M. Tintelecan
Keyword(s):  
Dimensional Accuracy ◽  
Wire Drawing ◽  
Wire Surface ◽  
Geometry Design ◽  
Strongly Connected ◽  
Specific Stage ◽  
Feature Based ◽  
The Wire ◽  
Correct Design ◽  
Important Activity

The most important activity of wire drawing technology is the correct design of stages geometry. The wire drawing within a roller die is described by an irregular deformation on wire width, strongly connected by the gauge shape between the rollers and cross section wire surface. Free lateral wire surface that has no contact with the roller on the deformation zone obstructs the wire elongation. There is a biunique correspondence between the shape and dimension of wire that enters between the rollers, and the free space between the rollers, corresponding to a specific stage of drawing. This has a great effect on dimensional accuracy of final wire. A drawing zone feature based model, allowed the examination of interaction evolution between wire and rolls geometry. This analysis helps the user of this technology to make a proper change in the arrangement and position of wire entering between rolls, or in the rolls configuration.

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