scholarly journals Analysis of Manufacturing Bimetallic Tubes by the Cold Drawing Process

2016 ◽  
Vol 61 (1) ◽  
pp. 241-248 ◽  
Author(s):  
D. Halaczek
Keyword(s):  
Solid State ◽  
Wall Thickness ◽  
Material Flow ◽  
Ferrous Metal ◽  
Cold Drawing ◽  
Drawing Process ◽  
Technological Parameters ◽  
Components Analysis ◽  
Copper Aluminum ◽  
Layer Composition

Drawing processes apply to obtain the bimetallic tubes from the different metals and alloys, combined in the solid state, which significantly affects the specificity of this process. The manufacturing of bimetallic tubes by drawing process depends on many factors which include: preparation of the surface of materials joined in the solid state, the geometric parameters of the working tool, technological parameters of the drawing process (drawing speed, type of lubricant, the use of back pull etc.). Generally, the cold drawing process of producing the bimetallic tubes refers to metals which have high ductility (copper, aluminum, etc.). The tube sinking (tube drawing without a mandrel) of bimetallic tubes together with joining them at the interface of the two metal in the solid-state is applied for tubes of the diameter range between 6 to 20 mm and based on of the reducing the diameter of the tube. However, a slight increase of wall thickness ca. 0.05 ÷ 0.10 mm can appear, which is not dangerous phenomenon in case of producing the bimetallic tubes by joining in the solid-state. The aim of the research was to investigate the technology of tubes drawing process from non-ferrous metal, drawing process of bimetallic tubes and the production of bimetallic tubes in layers composition: cooper Cu-ETP - brass CuZn37 and CuZn37 brass - copper Cu-ETP in the tube sinking process. The research program included: production of bimetallic tubes with a different composition (Cu- ETP-CuZn37 and CuZn37-Cu-ETP) and a different percentage of the cross-section components; analysis of changes of tube wall thickness and the layer composition of the bimetallic tube, based on measurements on the workshop microscope; analysis of the material flow in the process of the bimetallic tubes production based on the measurements results of a profilograph CP-200.

Variation of Residual Stresses in Drawn Copper Tubes

2008 ◽  
Vol 571-572 ◽  
pp. 21-26 ◽  
Author(s):  
Adele Carradò ◽  
D. Duriez ◽  
Laurent Barrallier ◽  
Sebastian Brück ◽  
Agnès Fabre ◽  
...  
Keyword(s):  
Neutron Diffraction ◽  
Residual Stresses ◽  
Material Flow ◽  
Cold Drawing ◽  
Axisymmetric Deformation ◽  
Tube Length ◽  
Inhomogeneous Deformation ◽  
Drawing Process ◽  
Process Step ◽  
Residual Strains

Seamless tubes are used for many applications, e.g. in heating, transport gases and fluids, evaporators as well as medical use and as intermediate products for hydroforming and various mechanical applications, where the final dimensions normally are given by some cold drawing steps. The first process step – piercing of the billet, for example by extrusion or 3-roll-milling - typically results in ovality and eccentricity in the tube causing non-symmetric material flow during the cold drawing process, i.e. inhomogeneous deformation. Because of this non-axisymmetric deformation and of deviations over tube length caused by moving tools, this process step generates residual stresses. To understand the interconnections between the geometrical changes in the tubes and the residual stresses, the residual strains in a copper tube had been measured by neutron diffraction.

Study on Wire Rod Drawing Process Using the Rotating Die

2016 ◽  
Vol 716 ◽  
pp. 63-67 ◽  
Author(s):  
Gow Yi Tzou ◽  
Dyi Cheng Chen ◽  
Shih Hsien Lin
Keyword(s):  
Velocity Field ◽  
Material Flow ◽  
Effective Strain ◽  
Fem Simulation ◽  
Cold Drawing ◽  
Drawing Process ◽  
Drawing Force ◽  
Wire Rod ◽  
Forming Characteristics ◽  
Deform 3D

This study proposes a cold drawing technology of wire rod with rotating die; it carries out an FEM simulation on rotating drawing using DEFORM-3D commercial software. Frictions among the die and the wire material are assumed as constant shear friction. The effective stress, the effective strain, the velocity field, and the drawing force can be determined from the FEM simulation. In this study, effects of various drawing conditions such as the rotating angular velocity, the half die angle, the frictional factor, the die filet on the drawing forming characteristics are explored effectively. From this FEM simulation, it is noted that the rotating die effect can reduce the drawing force and increase the material flow.

scholarly journals Towards Manufacturing of Ultrafine-Laminated Structures in Metallic Tubes by Accumulative Extrusion Bonding

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 389
Author(s):  
Matthew R. Standley ◽  
Marko Knezevic
Keyword(s):  
Solid State ◽  
Wall Thickness ◽  
Complex Geometry ◽  
Tube Wall ◽  
Film Theory ◽  
Radial Strain ◽  
Surface Preparation ◽  
Grain Structure ◽  
Outer Diameter ◽  
Laminated Structures

A severe plastic deformation process, termed accumulative extrusion bonding (AEB), is conceived to steady-state bond metals in the form of multilayered tubes. It is shown that AEB can facilitate bonding of metals in their solid-state, like the process of accumulative roll bonding (ARB). The AEB steps involve iterative extrusion, cutting, expanding, restacking, and annealing. As the process is iterated, the laminated structure layer thicknesses decrease within the tube wall, while the tube wall thickness and outer diameter remain constant. Multilayered bimetallic tubes with approximately 2 mm wall thickness and 25.25 mm outer diameter of copper-aluminum are produced at 52% radial strain per extrusion pass to contain eight layers. Furthermore, tubes of copper-copper are produced at 52% and 68% strain to contain two layers. The amount of bonding at the metal-to-metal interfaces and grain structure are measured using optical microscopy. After detailed examination, only the copper-copper bimetal deformed to 68% strain is found bonded. The yield strength of the copper-copper tube extruded at 68% improves from 83 MPa to 481 MPa; a 480% increase. Surface preparation, as described by the thin film theory, and the amount of deformation imposed per extrusion pass are identified and discussed as key contributors to enact successful metal-to-metal bonding at the interface. Unlike in ARB, bonding in AEB does not occur at ~50% strain revealing the significant role of more complex geometry of tubes relative to sheets in solid-state bonding.

scholarly journals Cold Forging Effect on the Microstructure of Motorbike Shock Absorbers Fabricated by Tube Forming in a Closed Die

2021 ◽  
Vol 11 (5) ◽  
pp. 2142
Author(s):  
Trung-Kien Le ◽  
Tuan-Anh Bui
Keyword(s):  
Material Flow ◽  
Cold Forging ◽  
Technological Parameters ◽  
Forming Process ◽  
Tube Forming ◽  
Shock Absorbers ◽  
Thin Walled Tube ◽  
Thin Walled ◽  
Quality Of Products ◽  
Forming Defects

Motorbike shock absorbers made with a closed die employ a tube-forming process that is more sensitive than that of a solid billet, because the tube is usually too thin-walled to conserve material. During tube forming, defects such as folding and cracking occur due to unstable tube forming and abnormal material flow. It is therefore essential to understand the relationship between the appearance of defects and the number of forming steps to optimize technological parameters. Based on both finite element method (FEM) simulations and microstructural observations, we demonstrate the important role of the number and methodology of the forming steps on the material flow, defects, and metal fiber anisotropy of motorbike shock absorbers formed from a thin-walled tube. We find limits of the thickness and height ratios of the tube that must be held in order to avoid defects. Our study provides an important guide to workpiece and processing design that can improve the forming quality of products using tube forming.

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.

Research on Combined Processing Technology of Superficial Layers Hardened Steel

2016 ◽  
Vol 841 ◽  
pp. 21-28
Author(s):  
Petrică Corabieru ◽  
Stefan Velicu ◽  
Anişoara Corabieru ◽  
Dan Dragos Vasilescu ◽  
Ionel Păunescu
Keyword(s):  
Solid State ◽  
Liquid Phase ◽  
Cooling Rate ◽  
Hold Time ◽  
Hardened Steel ◽  
Operating Conditions ◽  
Technological Parameters ◽  
Surface Layers ◽  
Durability Analysis ◽  
Machined Parts

The novelty technology lies in the fact that the hardening of the surface layers is carried out both in liquid phase and in the solid state. Technology comprises three main stages with 12 technological phases.Experimentation highlights the viability of the technological procedure. The results of tests and verifications are the basis of the analysis of combined machined parts behavior in conditions similar to the operating conditions and of the analysis of the dependence between operation behavior and durability. Analysis of the results revealed the fact that failure to technological parameters: casting temperature; hold time at high temperatures; cooling rate after microalloying in liquid phase, gives rise to possible faults of the combined treated parts.

scholarly journals Axial and Radial Material Flow Analysis in Infeed Rotary Swaging of Tubes

2018 ◽  
Vol 190 ◽  
pp. 04003 ◽  
Author(s):  
Yang Liu ◽  
Marius Herrmann ◽  
Christian Schenck ◽  
Bernd Kuhfuss
Keyword(s):  
Wall Thickness ◽  
Material Flow ◽  
Flow Direction ◽  
Flow Analysis ◽  
Material Flow Analysis ◽  
Relative Wall Thickness ◽  
Cold Forming ◽  
Rotary Swaging ◽  
Fundamental Insight ◽  
Actual Ratio

In rotary swaging – an incremental cold forming production technique to reduce the diameter of axisymmetric parts – the material flow can be assumed to be predominantly axial and radial. The actual ratio of this axial and radial flow influences the mechanical properties and especially in tube forming the final geometry. It is known that during mandrel free infeed rotary swaging of tubes the wall thickness changes. The change is depending on the process parameters like incremental and cumulated strain. Hence, the ratio of axial and radial material flow changes. Consequently, the analysis of the wall thickness of rotary swaged tubes enables fundamental insight how to control the material flow direction. In this study, the infeed rotary swaging process of steel tubes with different wall thicknesses from 3 mm to 7 mm and rods were investigated with FEM under two feeding velocities. The axial and radial material flow and the resulting geometry were studied by the relative wall thickness. It could be seen that the relative wall thickness was affected by the feeding velocity as well as the initial wall thickness. The findings of the simulation were validated by rotary swaging experiments.

scholarly journals The Recovery of Valuable Metals from Ocean Polymetallic Nodules Using Solid-State Metalized Reduction Technology

Minerals ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 20 ◽  
Author(s):  
Feng Zhao ◽  
Xunxiong Jiang ◽  
Shengdong Wang ◽  
Linyong Feng ◽  
Da Li
Keyword(s):  
Solid State ◽  
Magnetic Separation ◽  
Ferrous Metal ◽  
Mineral Resources ◽  
Metal Extraction ◽  
Metallic State ◽  
Ferrous Metals ◽  
Polymetallic Nodules ◽  
Valuable Metals ◽  
Pre Treatment

Ocean polymetallic nodules are oxide ores rich in Ni, Co, Cu, and Mn, which are valuable metals found in deep-sea mineral resources. Such non-ferrous metals do not exist in isolation, and producing concentrates using conventional mineral separation techniques is challenging without pre-treatment. We propose an effective, environmentally-friendly recovery technology combined with solid-state metalized reduction treatment and magnetic separation to recycle these metals from ocean polymetallic nodules. We conducted single-factor tests to investigate the effects of additives, anthracite dosage, duration, and reduction temperature on metal recovery and to obtain optimal operating parameters. We found that valuable metals in ocean polymetallic nodules may be selectively reduced to a metallic state. Only a fraction of Mn was reduced to metal. The reduced metals were recovered to concentrates using magnetic separation. More than 80% of these metals were concentrated to magnetic concentrates with mass ratios of 10–15%. The recovery rates of Ni, Co, Cu, Mn, and Fe in concentrates were optimum at 86.48%, 86.74%, 83.91%, 5.63%, and 91.46%, respectively, when using CaF2 4%, anthracite 7%, SiO2 dosage 5%, and FeS 6% at 1100 °C for 2.5 h. This approach to non-ferrous metal extraction using conventional hydrometallurgical processes could be a step toward practical industrial-scale techniques for the recovery of metals from polymetallic nodules.

scholarly journals Multi Draw Radius Die Design for Increases in Limiting Drawing Ratio

Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 870 ◽  
Author(s):  
Wiriyakorn Phanitwong ◽  
Sutasn Thipprakmas
Keyword(s):  
Deep Drawing ◽  
Material Flow ◽  
Rolling Direction ◽  
Die Design ◽  
Drawing Ratio ◽  
Drawing Process ◽  
Deep Drawing Process ◽  
Limiting Drawing Ratio ◽  
Proper Design ◽  
Main Barrier

As a major sheet metal process for fabricating cup or box shapes, the deep drawing process is commonly applied in various industrial fields, such as those involving the manufacture of household utensils, medical equipment, electronics, and automobile parts. The limiting drawing ratio (LDR) is the main barrier to increasing the formability and production rate as well as to decrease production cost and time. In the present research, the multi draw radius (MDR) die was proposed to increase LDR. The finite element method (FEM) was used as a tool to illustrate the principle of MDR based on material flow. The results revealed that MDR die could reduce the non-axisymmetric material flow on flange and the asymmetry of the flange during the deep drawing process. Based on this material flow characteristic, the cup wall stretching and fracture could be delayed. Furthermore, the cup wall thicknesses of the deep drawn parts obtained by MDR die application were more uniform in each direction along the plane, at 45°, and at 90° to the rolling direction than those obtained by conventional die application. In the present research, a proper design for the MDR was suggested to achieve functionality of the MDR die as related to each direction along the plane, at 45°, and at 90° to the rolling direction. The larger draw radius positioned for at 45° to the rolling direction and the smaller draw radius positioned for along the plane and at 90° to the rolling direction were recommended. Therefore, by using proper MDR die application, the drawing ratio could be increased to be 2.75, an increase in LDR of approximately 22.22%.

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