scholarly journals The Development of Technology and Equipment for Ultrasonic Seam Welding of Synthetic Fabrics

2019 ◽  
pp. 25-34
Author(s):  
S.S. Volkov ◽  
D.S. Rozanov ◽  
L.A. Shestel
Keyword(s):  
Welding Process ◽  
Heat Removal ◽  
Maximum Temperature ◽  
Thermal Processes ◽  
Welding Zone ◽  
Seam Welding ◽  
Warm Up ◽  
Support Roller ◽  
Welded Seam ◽  
Welding Pressure

In this work, possible methods of ultrasonic welding of synthetic fabrics are considered and analyzed. Technological features of ultrasonic seam welding of synthetic fabrics are described. The key parameters of this type of welding that significantly influence the speed of achieving the maximum temperature in the fabric welding zone are identified. These parameters determine the intensity of the fabrics’ warm-up, and therefore, the efficiency of the welding process. Thermal processes occurring at seam welding of synthetic fabrics are studied. It is established that the welding time increases with an increase in the number of connecting layers as well as with addition of cotton to the fabric composition. It is determined that when welding synthetic fabrics of small thickness, heat removal to the waveguide and the support roller has virtually no influence on the maximum temperature at the border of the mating surfaces and on the time of achieving the maximum temperature. Experiments on welding lavsan, kapron and polypropylene fabrics are conducted. The dependence of the statistic welding pressure on the welding speed and the fixed gap between the waveguide and the support roller is investigated. It is determined that the movement of material under the waveguide doesn not have a warming-up impact on the neighbouring areas of the welded seam. The strength of the welded joints practically does not depend on the height and shape of the support roller.

Computer Simulation of Thermal Processes in Arc Welding of Thick-Walled Aluminum Alloy Structures

2020 ◽  
pp. 12-20
Author(s):  
S.A. Korolev ◽  
A.E. Zimakov
Keyword(s):  
Computer Simulation ◽  
Finite Elements ◽  
Arc Welding ◽  
Geometric Model ◽  
Heat Removal ◽  
Thermal Processes ◽  
The Finite Element Method ◽  
Welding Zone ◽  
Welding Arc ◽  
Welded Structure

This paper presents the results of computer simulation of the thermal processes occurring during welding of thick-walled structures made of the AMg6 aluminium-magnesium alloy, widely used in modern industry. The model takes into account features associated with intensive heat removal from the welding zone caused by the large overall dimensions of the welded structure and the high thermal conductivity of the material used. In practice, these features increase the probability of formation of such defects as non-fusion of the weld with the base metal of the connected elements. Modeling was performed using the finite element method in the ANSYS software package. A geometric model was developed, and the bodies were divided into finite elements. For the areas with expected high temperature gradients, the finite elements in the geometric model were chosen to be much smaller than those in the areas further away from the welding zone. This increased the accuracy of the solution and significantly reduced the calculation time. The model of the heat source was constructed taking into account the gradual deposition of the weld metal as the welding arc moved along the connected edges. The simulation results confirmed the possibility of applying the available welding modes for the studied conditions.

scholarly journals Increasing of the Mechanical Properties of Friction Stir Welded Joints of 6061 Aluminum Alloy by Introducing Alumina Particles

2017 ◽  
Vol 17 (2) ◽  
pp. 29-40 ◽  
Author(s):  
M. A. Tashkandi ◽  
J. A. Al-Jarrah ◽  
M. Ibrahim
Keyword(s):  
Aluminum Alloy ◽  
Base Metal ◽  
Welded Joints ◽  
Volume Fraction ◽  
Welding Process ◽  
Welding Zone ◽  
6061 Aluminum Alloy ◽  
Friction Stir ◽  
Alumina Particles ◽  
Welding Line

AbstractThe main aim of this investigation is to produce a welding joint of higher strength than that of base metals. Composite welded joints were produced by friction stir welding process. 6061 aluminum alloy was used as a base metal and alumina particles added to welding zone to form metal matrix composites. The volume fraction of alumina particles incorporated in this study were 2, 4, 6, 8 and 10 vol% were added on both sides of welding line. Also, the alumina particles were pre-mixed with magnesium particles prior being added to the welding zone. Magnesium particles were used to enhance the bonding between the alumina particles and the matrix of 6061 aluminum alloy. Friction stir welded joints containing alumina particles were successfully obtained and it was observed that the strength of these joints was better than that of base metal. Experimental results showed that incorporating volume fraction of alumina particles up to 6 vol% into the welding zone led to higher strength of the composite welded joints as compared to plain welded joints.

Design and Optimization of a Composite Heat Spreader to Improve the Thermal Management of a 3D Integrated Circuit

2021 ◽  
Author(s):  
Andisheh Tavakoli ◽  
Kambiz Vafai
Keyword(s):  
Thermal Conductivity ◽  
Heat Sink ◽  
Variable Temperature ◽  
Heat Removal ◽  
High Conductivity ◽  
High Thermal Conductivity ◽  
Maximum Temperature ◽  
Optimal Distribution ◽  
Heat Spreader ◽  
The Impact

Abstract The present study analyzes the optimal distribution of a limited amount of high thermal conductivity material to enhance the heat removal of circular 3D integrated circuits, IC. The structure of the heat spreader is designed as a composite of high thermal conductivity (Boron Arsenide) and moderate thermal conductivity (copper) materials. The volume ratio of high-conductivity inserts to the total volume of the spreader is set at a fixed pertinent ratio. Two different boundary conditions of constant and variable temperature are considered for the heat sink. To examine the impact of adding high-conductivity inserts on the cooling performance of the heat spreader, various patterns of the single and double ring inserts are studied. A parametric study is performed to find the optimal location of the rings. Moreover, the optimal distribution of the high-conductivity material between the inner and outer rings is found. The results show that for the optimal conditions, the maximum temperature of the 3D IC is reduced up to 10%; while the size of the heat sink, and heat spreader can be diminished by as much as 200%.

Demonstration of Intelligent Welding Machine for Polyethylene Pipe

2021 ◽  
Author(s):  
Guangte Xiang ◽  
Yurui Hu ◽  
Sheng Zeng ◽  
Jianfeng Shi ◽  
Jinyang Zheng
Keyword(s):  
Welding Process ◽  
Maximum Temperature ◽  
Welding Parameters ◽  
Welding Time ◽  
Constant Voltage ◽  
Welding Machine ◽  
Reinforced Composite ◽  
Composite Pipe ◽  
The Difference

Abstract Electrofusion (EF) welding is one of the most common connection methods for polyethylene (PE) pipe, as well as thermoplastic pipe and reinforced composite pipe. Conventional EF welding generally adopts constant-voltage welding mode. The welding machine outputs a constant welding voltage to heat the resistance wire within specific welding time. In our previous study, intelligent welding machine was designed to ensure the quality of the EF joint, based on the study of the temperature field in EF joint. In this paper, three experiments were used to show the difference between the intelligent welding machine and traditional welding machine. The intelligent welding machine can actively adjust the welding parameters to ensure the quality of EF joint even it was given the wrong welding voltage and welding time. Compared with the traditional welding machine, the intelligent welding machine can automatically control the maximum temperature and the depth of melting region in EF joint during the welding process, and this method applies for EF joints with various diameters or design welding parameters.

An Effective Approach Based on Response Surface Methodology for Predicting Friction Welding Parameters

2016 ◽  
Vol 35 (3) ◽  
pp. 235-241
Author(s):  
Sare Celik ◽  
Aslan Deniz Karaoglan ◽  
Ismail Ersozlu
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Friction Welding ◽  
Welding Process ◽  
Raw Material ◽  
Maximum Temperature ◽  
Welding Parameters ◽  
Rotating Speed ◽  
Minimum Number ◽  
Normal Carbon

AbstractThe joining of dissimilar metals is one of the most essential necessities of industries. Manufacturing by the joint of alloy steel and normal carbon steel is used in production, because it decreases raw material cost. The friction welding process parameters such as friction pressure, friction time, upset pressure, upset time and rotating speed play the major roles in determining the strength and microstructure of the joints. In this study, response surface methodology (RSM), which is a well-known design of experiments approach, is used for modeling the mathematical relation between the responses (tensile strength and maximum temperature), and the friction welding parameters with minimum number of experiments. The results show that RSM is an effective method for this type of problems for developing models and prediction.

Effect of Tool Shape on Temperature Field in Friction Stir Spot Welding

2013 ◽  
Vol 58 (2) ◽  
pp. 595-599 ◽  
Author(s):  
P. Lacki ◽  
Z. Kucharczyk ◽  
R.E. Śliwa ◽  
T. Gałaczyński
Keyword(s):  
Temperature Field ◽  
Solid State ◽  
Spot Welding ◽  
Plastic Material ◽  
Welding Process ◽  
Friction Stir Spot Welding ◽  
Frictional Heat ◽  
Maximum Temperature ◽  
Tool Geometry ◽  
Friction Stir

Friction stir welding (FSW) is one of the youngest methods of metal welding. Metals and its alloys are joined in a solid state at temperature lower than melting points of the joined materials. The method is constantly developed and friction stir spot welding (FSSW) is one of its varieties. In the friction stir spot welding process a specially designed tool is brought into rotation and plunged, straight down, in the joined materials. Heat is generated as a result of friction between the tool and materials, and plastic deformation of the joined materials. Softening (plastic zone) of the joined materials occurs. Simultaneously the materials are stirred. After removal of the tool, cooling down the stirred materials create a solid state joint. Numerical simulation of the process was carried out with the ADINA System based on the finite element method (FEM). The problem was considered as an axisymmetric one. A thermal and plastic material model was assumed for Al 6061-T6. Frictional heat was generated on the contact surfaces between the tool and the joined elements. The model of Coulomb friction, in which the friction coefficient depends on the temperature, was used. An influence of the tool geometry on heat generation in the welded materials was analysed. The calculations were carried out for different radiuses of the tool stem and for different angles of the abutment. Temperature distributions in the welded materials as a function of the process duration assuming a constant value of rotational tool speed and the speed of tool plunge were determined. Additionally, the effect of the stem radius and its height on the maximum temperature was analysed. The influence of tool geometry parameters on the temperature field and the temperature gradient in the welded materials was shown. It is important regarding the final result of FSSW.

Technology-Based Re-Contouring of Blade Integrated Disks After Weld Repair

2018 ◽  
Author(s):  
B. Denkena ◽  
A. Mücke ◽  
T. Schumacher ◽  
D. Langen ◽  
T. Hassel
Keyword(s):  
End Milling ◽  
Welding Process ◽  
Milling Process ◽  
Grain Structure ◽  
Patch Repair ◽  
Shape Deviation ◽  
A Tig Welding ◽  
High Standards ◽  
The Individual ◽  
Welded Seam

The widespread adoption of blade integrated disks (blisks) made of titanium demands tailored re-generation processes to increase sustainability and economic efficiency. High standards regarding geometrical accuracy and functional properties as well as the unique characteristics of each type of damage complicate the repair. Thus, flexible and well-designed processes are necessary. Typically, material deposit is followed by a milling or grinding process to restore the original shape. Here, not only the individual repair processes have to be controlled, but also their interaction. For example, depending on the resulting microstructure of the welded seam, the re-contouring process needs to be adapted to minimize tool wear as well as shape deviations of the complex blade geometries. In this paper, the process chain for a patch repair is examined, consisting of a TIG welding process followed by 5-axis ball nose end milling. Conventional TIG as well as a modified TIG process producing a finer grain structure and enhanced mechanical properties of deposited material were investigated. Grain refinement was achieved by SiC particles added to the weld pool. Based on the characteristics of the fusion material and static stiffness of the component, a methodology is introduced to minimize shape deviation induced by the subsequent milling process. Special attention is given to tool orientation, which has a significant impact on the kinematics and resulting process forces during milling. An electromagnetic guided machine tool is used for compensation of workpiece deflection.

Linear Friction Welding of IN-718 Process Optimization and Microstructure Evolution

2006 ◽  
Vol 15-17 ◽  
pp. 357-362 ◽  
Author(s):  
Caroline Mary ◽  
Mohammad Jahazi
Keyword(s):  
Process Parameters ◽  
Microstructure Evolution ◽  
Friction Welding ◽  
Welding Process ◽  
Weld Interface ◽  
Maximum Temperature ◽  
Linear Friction Welding ◽  
Influence Of Process Parameters ◽  
Linear Friction ◽  
The Matrix

Linear Friction Welding (LFW) of IN-718 Superalloy was investigated under several processing conditions. The influence of process parameters such as frequency (60Hz to 100Hz), amplitude (2mm to 3mm) and frictional pressure (50MPa to 110MPa) on the microstructure and mechanical properties of welded specimens was determined. Optical and scanning electron microscopy, and micro-hardness testing were used to characterize the welded areas as well as the Thermo-Mechanically Affected Zones (TMAZ). In-situ thermocouple measurements were performed to follow temperature evolution in the specimens during the different phases of the LFW process. The analysis of the results indicated that for some specific conditions (f=80Hz, a=2mm and P=70MPa) a maximum temperature of 1200°C was attained during the last stage of the welding process, the burn-off phase. This temperature, very close to the alloy melting range, would be sufficient to cause partial liquation in this zone. Microscopic examinations revealed the presence of oxide particles aligned around the weld interface. Their concentration and distribution, varying with process parameters, affect the weld integrity. The TMAZ characterised by a global loss of strength (from 334HV to 250HV) is associated with temperatures exceeding 800°C and causing γ’ and γ’’ reversion. A narrow band of the TMAZ, exposed to high strains and temperatures, showed evidences of dynamic recovery and recrystallization (up to 67% of reduction in the matrix grain size). Visual and microscopic examination of the flash layer, revealed two distinct zones. Microstructure evolution and microhardness variations were associated to process parameters and the optimum conditions for obtaining defect free weldments were determined.

A Novel Approach to Process Modeling for Ultrasonic Plastics Welding

2010 ◽  
Author(s):  
M. Ying ◽  
C. K. Cheng ◽  
J. Wei
Keyword(s):  
Process Parameters ◽  
Process Modeling ◽  
Welding Process ◽  
Ultrasonic Welding ◽  
Dissipated Energy ◽  
Measured Temperature ◽  
Novel Approach ◽  
Interfacial Temperature ◽  
Welding Pressure ◽  
Fully Coupled

Ultrasonic plastics welding is a widely employed joining technique for thermoplastic polymer assembly nowadays. As one fusion joining method, the ultrasonic welding quality is mainly dependent on the interfacial temperature which is affected by many process factors, such as welding time, welding pressure, and vibration amplitude, as well as material properties. Many attempts have been made to understand the mechanism of creation of an ultrasonic weld but limited by the complexity of the welding process. The current study developed a novel approach to process modeling for ultrasonic plastics welding. The thermoplastic materials were characterized with time domain viscoelastic model. The energy dissipation by the viscoelasticity was converted into the heating source which caused the temperature rose. The temperature change affected the material and structure responses and eventually the dissipated energy. As such, a fully coupled thermal-stress finite element (FE) model was established to simulate the performances of the ultrasonic welding. With the fully coupled model, the temperature distribution and displacement could be solved accurately and simultaneously. Meanwhile, the interfacial temperature was experimentally measured under the different process parameters. The simulation model was further validated by the measured temperature. With this novel approach, the ultrasonic plastics welding process can be completely simulated and the process parameters can be optimized numerically.

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