scholarly journals Investigation of the workability and surface roughness of thin brass wires in various dieless drawing technologies

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Andrij Milenin ◽  
Mirosław Wróbel ◽  
Piotr Kustra
Keyword(s):  
Surface Roughness ◽  
Deformation Temperature ◽  
Longitudinal Strain ◽  
Drawing Process ◽  
Thin Wire ◽  
Dieless Drawing ◽  
Quality Product ◽  
Product Surface ◽  
The Wire ◽  
The One

AbstractPossibilities of improving the workability of the CuZn37 brass thin wire in a diameter of 0.14–0.18 mm produced by the dieless drawing processes were explored. The workability was defined as the maximum final longitudinal strain of the wire up to its fracture, achievable in the dieless drawing process. Two technologies of dieless drawing were developed and their workability was compared. The first one is the classical one-pass process; the second, a multi-pass one. For both developed technologies, it was possible to obtain a good-quality product but more than two times higher workability has been demonstrated for the multi-pass technology. No evident effect of the deformation temperature from the window of technologically accepted parameters on the workability was found but an increase in the temperature significantly increased the roughness of the product surface. For the same deformation temperature, the roughness of the wire obtained from the multi-pass process appeared to be significantly lower than for the one of the classical one-pass technologies.

Physical Modelling of Strain Induced Roughness of Copper Wire during Dieless Drawing Process

2021 ◽  
Vol 1016 ◽  
pp. 900-905
Author(s):  
Andrij Milenin ◽  
Dorota Byrska-Wójcik ◽  
Mirosław Wróbel
Keyword(s):  
Experimental Study ◽  
Surface Roughness ◽  
Numerical Modeling ◽  
Deformation Temperature ◽  
Copper Wire ◽  
Physical Modelling ◽  
Significant Problem ◽  
Drawing Process ◽  
Dieless Drawing ◽  
The Wire

One of the possibilities of the dieless drawing is the production of ultrafine wire. In this case, it is possible for additionally stretch the wire, obtained in the conventional way. This may allow to obtain a wire of smaller diameter than the industry produces. However, the significant problem is the increase of the strain induced roughness of wire during dieless drawing. This problem has become important due to the fact that the resulting roughness can be comparable to the diameter of the wire and significantly reduce the workability. Thus, the solution of these problems requires plastometric studies of the material, physical and numerical modeling for prediction the roughness of the wire under conditions of dieless drawing. The experimental study shown, that the surface roughness of the copper wire after dieless drawing increases significantly at a deformation temperature above 300°C. The total roughness is associated both with the formation of oxides and the strain induced roughness.

scholarly journals Transformation of Surface Roughness of Mg Alloy Tubes During Laser Dieless Drawing

2020 ◽  
Vol 29 (11) ◽  
pp. 7736-7743
Author(s):  
Andrij Milenin ◽  
Tsuyoshi Furushima ◽  
Jiří Němeček
Keyword(s):  
Surface Roughness ◽  
Longitudinal Strain ◽  
Maximum Stress ◽  
Experimental Studies ◽  
Strain Curve ◽  
Surface Roughening ◽  
Drawing Process ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Dieless Drawing

AbstractThe paper investigates the transformation of surface roughness of tubes made from magnesium and magnesium alloys as a function of their longitudinal strain during laser dieless drawing. Experimental studies on three materials (AZ31, MgCa08, and pure Mg) have shown that the dependence of roughness on the longitudinal strain is nonlinear and exhibits a minimum. The proposed explanation for this is that the transformation of surface roughness occurs following two mechanisms. The first mechanism involves stretching of the tube and the decreasing of existing roughness with the increasing elongation. The second mechanism is based on the strain-induced surface roughening phenomenon. This mechanism leads to an increase in roughness with the increasing elongation. To analyze these mechanisms, a numerical model of roughness formation is used. It is experimentally shown that the position of the minimum roughness concerning the tube longitudinal strain is correlated with the stress-strain curve of the material under laser dieless drawing conditions. The obtained results provide a practical way to reduce surface roughness of tubes produced by the laser dieless drawing process. According to the proposed method, to achieve minimum roughness, it is necessary to keep the longitudinal strain under a specific value. This value is close to the strain, which corresponds to the maximum stress on the stress-strain curve of the material for temperature and strain rate, corresponding laser dieless drawing conditions.

Experimental and numerical analysis of the deformation in mild steel wire during dieless drawing

2002 ◽  
Vol 216 (3) ◽  
pp. 167-178 ◽  
Author(s):  
P Tiernan ◽  
M T Hillery
Keyword(s):  
Mild Steel ◽  
Steel Wire ◽  
Wire Drawing ◽  
Fe Model ◽  
Drawing Process ◽  
Distribution Profile ◽  
Dieless Drawing ◽  
The Wire ◽  
Drawing Dies ◽  
Good Agreement

Dieless wire drawing is the process of causing a reduction in a wire diameter without the use of conventional wire drawing dies. The wire, axially loaded with a force, is heated to an elevated temperature to initiate plastic deformation. The mechanics of this novel drawing process and a theoretical analysis of the deformation are discussed in this paper. The results of an experimental drawing programme carried out with mild steel wire at temperatures between 400 and 900°C are also presented. Mathematical models were developed and used to describe and predict the process deformation and both the stress and temperature distribution profile along the workpiece. A machine was designed and manufactured to facilitate an experimental programme of dieless drawing. The machine permitted continuous drawing of wire, while the reduction ratio, drawing load and temperature were automatically controlled using a personal computer. A finite element (FE) model of the wire was developed, and the results obtained from the FE analysis show good agreement with those obtained from both the experimental work and the mathematical modelling. Results obtained confirm that a complicated interdependence of the process parameters exists during the dieless drawing process.

scholarly journals Functional design of sonotrodes for deep-drawing of cardboard

BioResources ◽  
2020 ◽  
Vol 15 (2) ◽  
pp. 2763-2773
Author(s):  
Albrecht Löwe ◽  
Anke Nikowski ◽  
Marek Hauptmann
Keyword(s):  
Surface Roughness ◽  
Deep Drawing ◽  
Vibration Mode ◽  
Influencing Factor ◽  
Vertical Vibration ◽  
Material Surface ◽  
Drawing Process ◽  
Functional Design ◽  
Shape Deviation ◽  
The One

The functional design of ultrasonic sonotrodes for deep-drawing is considered. The achievable stability, shape deviation, and surface roughness of deep-drawn cups were determined as a function of the vibration mode, the vibration amplitude, and the contact pressure as it occurs in the gap between the tools. Because the development of sonotrodes is complex and expensive, substitute experiments were conducted that allowed the cup parameters to be determined even without the manufacture of numerous sonotrodes, thus minimizing the effort involved. The results showed that the vibration mode, which determines the angle at which the vibration hits the material surface, is the most important influencing factor. The best way to increase stability and reduce shape deviation and surface roughness is to use an oscillation that hits the material surface perpendicularly during the entire deep-drawing process. With perpendicular vibration, the strength of the cup wall increased up to 200% compared to the one produced without ultrasound. The surface roughness could be reduced to 50% with the vertical vibration compared to without ultrasonic support.

scholarly journals Experimental and Numerical Study of Surface Roughness of Thin Brass Wire Processed by Different Dieless Drawing Processes

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 35
Author(s):  
Andrij Milenin ◽  
Mirosław Wróbel ◽  
Piotr Kustra ◽  
Jiří Němeček
Keyword(s):  
Mechanical Properties ◽  
Surface Roughness ◽  
Numerical Study ◽  
Lower Surface ◽  
Surface Shape ◽  
Wire Surface ◽  
Dieless Drawing ◽  
The Wire ◽  
Small Increments ◽  
Brass Wire

This paper examines the surface roughness of a thin brass wire (140–200 microns in diameter) after two dieless drawing (DD) processes, i.e., conventional dieless drawing (CDD) and incremental dieless drawing (IDD). In incremental dieless drawing, small increments in deformation were applied in several passes. It has been proven that the IDD process not only has a greater efficiency but also enables obtaining a wire with significantly lower surface roughness. The explanation for these effects is based on the results of the numerical modeling of both compared processes. The developed numerical model takes into consideration the initial roughness of the wire surface, shape and dimensions of grains, and their diversified mechanical properties. Nanoindentation measurements, microstructure, and plastometric studies allowed us to find the effective flow stress distribution in the grains. The IDD process was found to be much more stable and develop a much more uniform distribution of grain strain than the CDD process. More homogeneous deformation results in surface roughness reduction. Approximately 25–30% reduction in surface roughness of the wire produced by the IDD process was predicted by simulations and confirmed experimentally.

scholarly journals Deep Learning Approach for Vibration Signals Applications

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3929
Author(s):  
Han-Yun Chen ◽  
Ching-Hung Lee
Keyword(s):  
Surface Roughness ◽  
Tool Wear ◽  
Parameters Optimization ◽  
Frequency Spectra ◽  
Vibration Signals ◽  
Bearing Faults ◽  
Time Frequency ◽  
And Performance ◽  
The One ◽  
Short Time

This study discusses convolutional neural networks (CNNs) for vibration signals analysis, including applications in machining surface roughness estimation, bearing faults diagnosis, and tool wear detection. The one-dimensional CNNs (1DCNN) and two-dimensional CNNs (2DCNN) are applied for regression and classification applications using different types of inputs, e.g., raw signals, and time-frequency spectra images by short time Fourier transform. In the application of regression and the estimation of machining surface roughness, the 1DCNN is utilized and the corresponding CNN structure (hyper parameters) optimization is proposed by using uniform experimental design (UED), neural network, multiple regression, and particle swarm optimization. It demonstrates the effectiveness of the proposed approach to obtain a structure with better performance. In applications of classification, bearing faults and tool wear classification are carried out by vibration signals analysis and CNN. Finally, the experimental results are shown to demonstrate the effectiveness and performance of our approach.

Heat Assisted Dieless Drawing Process of Superplastic Metal Microtubes - From Zn22Al to β Titanium Alloys

2016 ◽  
Vol 838-839 ◽  
pp. 459-467 ◽  
Author(s):  
Tsuyoshi Furushima ◽  
Ken-Ichi Manabe
Keyword(s):  
Cross Sections ◽  
Rate Sensitivity ◽  
Sensitivity Index ◽  
Outer Diameter ◽  
Drawing Process ◽  
Initial Shape ◽  
Dieless Drawing ◽  
Superplastic Alloy ◽  
Strain Rate Sensitivity Index ◽  
Contact Situation

A heat assisted superplastic dieless drawing process that requires no dies or tools is applied to the drawing of a Zn-22Al and β titanium superplastic alloy for not only circular but also noncircular microtubes such as square, rectangular and noncircular multi core tubes having square inner and rectangular outer cross sections. As a result, the tendency has been to increase the limiting reduction in area with increasing strain rate sensitivity index m value. We successfully fabricate Zn-22Al alloy, AZ31 magnesium, β titanium circular microtubes with outer diameter of 191μm, 890μm and 180μm, respectively. Furthermore, a noncircular micro tube, which has inner square tubes with a 335μm side, and an outer rectangular tube of 533×923μm were fabricated successfully. During the dieless drawing process, the geometrical similarity law in cross section which the tube is drawn while maintaining its initial shape can be satisfied. The smooth surface can be obtained in case of superplastic dieless drawing process without contact situation with dies and tools. Consequently, it is found that the superplastic dieless drawing is effective for the fabrication of circular and noncircular multicore microtubes.

scholarly journals Adjustment of Wire Vibrations in Order to Improve Geometric Accuracy and Surface Roughness at WEDM

2021 ◽  
Vol 11 (11) ◽  
pp. 4734
Author(s):  
Ľuboslav Straka ◽  
Ivan Čorný
Keyword(s):  
Surface Roughness ◽  
Economic Efficiency ◽  
Acoustic Emissions ◽  
Tool Electrode ◽  
Geometric Accuracy ◽  
Dynamic Adjustment ◽  
Machined Surface ◽  
Minimal Impact ◽  
The Wire ◽  
Wedm Process

Although WEDM is one of the most precise finishing technologies, deviations from the required geometric shapes and surface roughness occur in the production of parts with rotary surfaces. Even though these shortcomings have only a minimal impact on planar cuts, the production of circular profiles is a different problem. One of the factors causing this poor quality is the vibration of the wire electrode. With appropriate vibration adjustment, it would be possible to achieve significant improvements of the eroded area quality, both in terms of geometric accuracy and in terms of surface roughness. This would significantly increase quality, enabling WEDM technology to compete with other technologies in terms of economic efficiency. Therefore, the proposed solution aims to provide a partial adjustment to the wire tool electrode vibrations, based on their sensing by the means of acoustic emissions or a laser beam, with subsequent dynamic adjustment of the actual technological parameter values. This way, the given solution will increase the production accuracy of circular holes, increase productivity, and ultimately provide an overall increase in the economic efficiency of the WEDM process. The article also presents the scheme of a control algorithm for monitoring and subsequent adjustments of the vibrations of the wire tool electrode during the electroerosion process in order to minimize geometric deviations of circularity, cylindricity and roughness of the machined surface.

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