scholarly journals Effects of Different Roller Profiles on the Microstructure and Peel Strength of the Ultrasonic Welding Joints of Nonwoven Fabrics

2020 ◽  
Vol 10 (12) ◽  
pp. 4101
Author(s):  
Thanh-hai Nguyen ◽  
Le Quang Thanh ◽  
Nguyen Huu Loc ◽  
Manh Ngo Huu ◽  
Anh Nguyen Van
Keyword(s):  
Manufacturing Industry ◽  
Welding Process ◽  
Peel Strength ◽  
Ultrasonic Welding ◽  
Water Repellent ◽  
Nonwoven Fabrics ◽  
Melted Zone ◽  
Welding Defects ◽  
Resilient Functions ◽  
Welding Joints

Nonwoven fabrics are widely used in the textile manufacturing industry due to their advanced characteristics, such as their soft, water-repellent, recycle, ecological, and resilient functions. Nowadays, one of the innovated technologies applied to bond nonwoven fabrics is the ultrasonic welding method, due to the advantages afforded by its clean, fast, and reliable approach. In this work, isotactic polypropylene (PP) nonwoven fabrics were bonded by a continuous ultrasonic welding process. In order to consider the influence of the roller on the formation of welding joints and their mechanical properties, different roller profiles were designed, fabricated, and tested. Eight types of roller profiles corresponding to No. 1–No. 8 in the experiments were divided into four groups. After bonding, the microstructure in a typical case (i.e., No. 1) was captured by scanning electron microscopy (SEM) to examine the formation of the welding joints. Additionally, the load and the peel strength of the welding joints of all eight roller profiles were analyzed. The results showed that no welding defects, such as cracks or blowholes, were visible in the melted zone. The load depended on the area ratio(s) of the welding area (S0) to the cycling area (S1). Furthermore, it was found out that the peel strength of the welding joints with brick structures were higher than the peel strength in the case of solid line structures.

scholarly journals Investigation of Interfacial Microstructure and Tensile Strength of Ultrasonic Welding Joints on Nonwoven Fabrics

2020 ◽  
Author(s):  
Hai T. Nguyen ◽  
Quang Le ◽  
Loc Nguyen ◽  
Ngo Huu Manh ◽  
Nguyen Van Anh
Keyword(s):  
Tensile Strength ◽  
Manufacturing Industry ◽  
Ultrasonic Welding ◽  
Interfacial Microstructure ◽  
Carbon Steels ◽  
Water Repellent ◽  
Sem Images ◽  
Element Analysis ◽  
Nonwoven Fabrics ◽  
Welding Joints

Nonwoven fabrics have been widely used in textile manufacturing industry as a sheet or web structure because of soft, water-repellent, recycle, ecological and resilient functions. Ultrasonic welding method has been applied for bonding nonwoven fabrics due to clean, fast and reliable approach. In this work, the ultrasonic stepped horn is designed to generate uniform amplitudes on the working surface by using finite element analysis (FEA) simulation. Chromium carbon steels are utilized to produce ultrasonic horns due to high wear resistant and hardness. Isotactic polypropylene nonwoven fabrics fabricated by spunbond process were bonded by continuous ultrasonic sewing machine. Ultrasonic horn with 70 mm in diameter working at 20 kHz, polypropylene (PP) nonwoven density of 80 gsm and various design of welding joints were applied. A typical image in the case of number one was investigated by the scanning electron microscope (SEM) images of inter-facial micro-structure. However, welding joints of totally eight roller patterns was test the tensile strength of the ultrasonic welding joints on PP nonwoven fabrics. The tensile strength of the welding joints is proportional to the area ratio between the welding area and cycling area. The results showed that the melted zone without welding defects such as crack or blowhole can be seen. Furthermore, the tensile strength of welding joints in eight cases of roller patterns (No.1-No.8) was described in details. The ultrasonic welding joints with brick structures give higher tensile strength while the solid line in the pattern gave less strength.

scholarly journals Investigation of Imperfections Formed at the Ultrasonic Welding of Copper Sheets

2019 ◽  
Vol 2 (1) ◽  
pp. 43-48
Author(s):  
Tünde Anna Kovács
Keyword(s):  
Colour Change ◽  
Welding Process ◽  
Ultrasonic Welding ◽  
Welding Parameters ◽  
Dissimilar Metals ◽  
Thin Sheets ◽  
Work Time ◽  
Welding Defects

Abstract Ultrasonic welding is a very useful and simple welding process. It is suitable for establishing a joint between thin sheets and dissimilar metals with short preparation and finish work time [1]. Some welding defects were detected due to less than optimal ultrasonic welding parameters. These defects were ruptures, surface colour change and unacceptable deformations. This article aims to identify these failures and their causes.

scholarly journals Porosity Defect Analysis in ST 37 Steel Welding Joints Using the Dye Penetrant Method

Teknomekanik ◽  
2020 ◽  
Vol 3 (1) ◽  
pp. 1-8
Author(s):  
Alan Wari ◽  
Hendri Nurdin ◽  
Kyaw Zay Ya
Keyword(s):  
Welding Process ◽  
Quality Standards ◽  
Test Study ◽  
Welding Defects ◽  
Porosity Defects ◽  
Welding Joints ◽  
Dye Penetrant ◽  
Definition Of ◽  
Non Destructive ◽  
Welding Position

The procedures in the world of welding all look simple, but all welding that looks simple must have extensive knowledge in accordance with the definition of welding. This welding is a permanent connection technique, when the welding process takes place the results do not always meet the quality standards that have been determined. The cause of the welding results that do not meet the quality standards in the form of dirt on the material when before welding and so forth. The purpose of this study is that the specimen specimens are accepted according to the welding institute's standard acceptance criteria (TWI) This research uses st 37 steel by using SMAW welding electrodes LB 52U (E 7016) diameter 2.6mm for root, and LB 52U (E 7016) diameter 3.2 for fillers and caping with welding position 1G. Testing of welding results is carried out by the non destructive test of the dye penetrant method whose inspection results are determined based on the standard ASME. The results of this test study discontinuity in the form of porosity on the surface of the welding results in specimen 1, namely material contaminated by dirt, there are porosity defects scattered with a length of 6mm and porosity of 10mm so based on the standard TWI both test specimens were declared rejected, and in specimen 2, material that was not contaminated with impurities, there were porosity defects of 2mm and 2.5mm so that according to the standards of the two specimens the test was accepted. For the results of welding defects that are rejected can still be corrected by linking to the defects that, and can be done welding again.

scholarly journals Quality evaluation of welding joints by different methods

2020 ◽  
Vol 48 (4) ◽  
pp. 816-824
Author(s):  
Miroslava Ťavodová ◽  
Nataša Náprstková ◽  
Michaela Hnilicová ◽  
Pavel Beňo
Keyword(s):  
Quality Evaluation ◽  
Welding Process ◽  
Metallographic Analysis ◽  
Management Tools ◽  
Weld Joints ◽  
Welding Defects ◽  
Piping Systems ◽  
Industrial Energy ◽  
Welding Joints ◽  
Cause And Effect Diagram

This paper presents the results of the quality evaluation of the weld joints on welded pipes used in industrial energy. The quality evaluation of the weld joints was performed by two methods. Using technical methods, welding faults and defects were examined, identified and evaluated by a metallographic analysis on the macrostructure of welds. According to ISO 6520-1:2007, the faults and defects were detected and classified into the group and classified into quality levels using ISO 5817:2008-03. Two quality management tools using a Cause and effect diagram - Iskihawa diagram and a Pareto diagram also evaluated the quality control of welds. These two tools enabled to identify the causes of welding defects as well as to determine the frequency of their occurrence and to identify the most serious welding faults and defects. Both methods - technical and management, should reveal shortcomings in both technical, technological and personnel aspect. Their use should contribute to improving the welding process of pipes in operation and to increasing the safety of piping systems.

scholarly journals Static ultrasonic welding of carbon fibre unidirectional thermoplastic materials and the influence of heat generation and heat transfer

2021 ◽  
pp. 002199832097681
Author(s):  
F Köhler ◽  
IF Villegas ◽  
C Dransfeld ◽  
A Herrmann
Keyword(s):  
Cross Sections ◽  
Weld Line ◽  
Welding Process ◽  
Ultrasonic Welding ◽  
Thermoplastic Composites ◽  
Squeeze Flow ◽  
Anisotropic Flow ◽  
Lap Shear ◽  
Anisotropic Thermal Conductivity ◽  
Edge Defects

Ultrasonic welding is a promising technology to join fibre-reinforced thermoplastic composites. While current studies are mostly limited to fabric materials the applicability to unidirectional materials, as found in aerospace structures, would offer opportunities for joining primary aircraft structures. However, due to the highly anisotropic flow of a molten unidirectional ply undesired squeeze flow phenomena can occur at the edges of the weld overlap. This paper investigates how the fibre orientation in the plies adjacent to the weld line influences the welding process and the appearance of edge defects. Ultrasonic welding experiments with different layups and energy director configurations were carried out while monitoring temperatures at different locations inside and outside the weld overlap. The joints were characterized by single lap shear tests, analysis of corresponding fracture surfaces and microscopic cross-sections. Results showed that the anisotropic flow and the anisotropic thermal conductivity of the plies adjacent to the weld line have a distinct effect on the appearance and location of edge defects. By using energy directors that cover only part of the weld overlap area a new approach was developed to mitigate edge defects caused by the highly directional properties of the unidirectional plies.

Experimental Investigations on Aluminium Ultrasonic Welding Parameters

2014 ◽  
Vol 657 ◽  
pp. 306-310
Author(s):  
Lăcrămioara Apetrei ◽  
Vasile Rață ◽  
Ruxandra Rață ◽  
Elena Raluca Bulai
Keyword(s):  
Microstructural Analysis ◽  
Base Material ◽  
Welding Process ◽  
Ultrasonic Welding ◽  
Experimental Investigations ◽  
Welding Parameters ◽  
Material Structure ◽  
Welding Temperature ◽  
Wide Range ◽  
Made In

Research evolution timely tendencies, in the nonconventional technologies field, are: manufacture conditions optimization and complex equipments design. The increasing of ultrasonic machining use, in various technologies is due to the expanding need of a wide range materials and high quality manufacture standards in many activity fields. This paper present a experimental study made in order to analyze the welded zone material structure and welding quality. The effects of aluminium ultrasonic welding parameters such as relative energy, machining time, amplitude and working force were compared through traction tests values and microstructural analysis. Microhardness tests were, also, made in five different points, two in the base material and three in the welded zone, on each welded aluminium sample. The aluminum welding experiments were made at the National Research and Development Institute for Welding and Material Testing (ISIM) Timişoara. The ultrasonic welding temperature is lower than the aluminium melting temperature, that's so our experiments reveal that the aluminium ultrasonic welding process doesn't determine the appearance of moulding structure. In the joint we have only crystalline grains deformation, phase transformation and aluminium diffusion.

Transient Temperature and Heat Flux Measurement in Ultrasonic Joining of Battery Tabs Using Thin-Film Microsensors

2013 ◽  
Vol 135 (5) ◽  
Author(s):  
Hang Li ◽  
Hongseok Choi ◽  
Chao Ma ◽  
Jingzhou Zhao ◽  
Hongrui Jiang ◽  
...  
Keyword(s):  
Thin Film ◽  
Heat Flux ◽  
Heat Generation ◽  
Welding Process ◽  
Ultrasonic Welding ◽  
Transient Temperature ◽  
Monitoring And Control ◽  
Change Rate ◽  
Flux Change ◽  
And Control

Process physics understanding, real time monitoring, and control of various manufacturing processes, such as battery manufacturing, are crucial for product quality assurance. While ultrasonic welding has been used for joining batteries in electric vehicles (EVs), the welding physics, and process attributes, such as the heat generation and heat flow during the joining process, is still not well understood leading to time-consuming trial-and-error based process optimization. This study is to investigate thermal phenomena (i.e., transient temperature and heat flux) by using micro thin-film thermocouples (TFTC) and thin-film thermopile (TFTP) arrays (referred to as microsensors in this paper) at the very vicinity of the ultrasonic welding spot during joining of three-layered battery tabs and Cu buss bars (i.e., battery interconnect) as in General Motors's (GM) Chevy Volt. Microsensors were first fabricated on the buss bars. A series of experiments were then conducted to investigate the dynamic heat generation during the welding process. Experimental results showed that TFTCs enabled the sensing of transient temperatures with much higher spatial and temporal resolutions than conventional thermocouples. It was further found that the TFTPs were more sensitive to the transient heat generation process during welding than TFTCs. More significantly, the heat flux change rate was found to be able to provide better insight for the process. It provided evidence indicating that the ultrasonic welding process involves three distinct stages, i.e., friction heating, plastic work, and diffusion bonding stages. The heat flux change rate thus has significant potential to identify the in-situ welding quality, in the context of welding process monitoring, and control of ultrasonic welding process. The weld samples were examined using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) to study the material interactions at the bonding interface as a function of weld time and have successfully validated the proposed three-stage welding theory.

scholarly journals Monitoring of the ultrasonic welding process

2020 ◽  
Author(s):  
M. Kornely ◽  
J. Rittmann ◽  
M. Kreutzbruck
Keyword(s):  
Welding Process ◽  
Ultrasonic Welding

scholarly journals Analysis of the influence of position of welding materials on the FSW seams properties for three dissimilar aluminium alloy

2018 ◽  
Vol 178 ◽  
pp. 03003 ◽  
Author(s):  
Ana Bosneag ◽  
Marius Adrian Constantin ◽  
Eduard Niţu ◽  
Monica Iordache
Keyword(s):  
Friction Stir Welding ◽  
Aluminium Alloy ◽  
Process Parameters ◽  
Arc Welding ◽  
Welding Process ◽  
Dissimilar Materials ◽  
Workpiece Material ◽  
Friction Stir ◽  
Welding Joints ◽  
Welding Materials

Friction Stir Welding, abbreviated FSW is a new and innovative welding process. This welding process is increasingly required, more than traditional arc welding, in industrial environment such us: aeronautics, shipbuilding, aerospace, automotive, railways, general fabrication, nuclear, military, robotics and computers. FSW, more than traditional arc welding, have a lot of advantages, such us the following: it uses a non-consumable tool, realise the welding process without melting the workpiece material, can be realised in all positions (no weld pool), results of good mechanical properties, can use dissimilar materials and have a low environmental impact. This paper presents the results of experimental investigation of friction stir welding joints to three dissimilar aluminium alloy AA2024, AA6061 and AA7075. For experimenting the value of the input process parameters, the rotation speed and advancing speed were kept the same and the position of plates was variable. The exit date recorded in the time of process and after this, will be compared between them and the influence of position of plate will be identified on the welding seams properties and the best position of plates for this process parameters and materials.

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