DOCSLIB.ORG

0021998315614991 Publication Date 2016 Document Version Final Published Version Published in Journal of Composite Materials

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
0021998315614991 Publication Date 2016 Document Version Final Published Version Published in Journal of Composite Materials Delft University of Technology Modeling and experimental investigation of induction welding of thermoplastic composites and comparison with other welding processes Gouin O'Shaughnessey, Patrice; Dube, M; Fernandez Villegas, Irene DOI 10.1177/0021998315614991 Publication date 2016 Document Version Final published version Published in Journal of Composite Materials Citation (APA) Gouin O'Shaughnessey, P., Dube, M., & Fernandez Villegas, I. (2016). Modeling and experimental investigation of induction welding of thermoplastic composites and comparison with other welding processes. Journal of Composite Materials, 50(21), 2895-2910. https://doi.org/10.1177/0021998315614991 Important note To cite this publication, please use the final published version (if applicable). Please check the document version above. Copyright Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons. Takedown policy Please contact us and provide details if you believe this document breaches copyrights. We will remove access to the work immediately and investigate your claim. This work is downloaded from Delft University of Technology. For technical reasons the number of authors shown on this cover page is limited to a maximum of 10. JOURNAL OF COMPOSITE Article MATERIALS Journal of Composite Materials 2016, Vol. 50(21) 2895–2910 ! The Author(s) 2015 Modeling and experimental investigation Reprints and permissions: sagepub.co.uk/journalsPermissions.nav of induction welding of thermoplastic DOI: 10.1177/0021998315614991 jcm.sagepub.com composites and comparison with other welding processes Patrice Gouin O’Shaughnessey1, Martine Dube´ 1 and Irene Fernandez Villegas2 Abstract A three-dimensional finite element model of the induction welding of carbon fiber/polyphenylene sulfide thermoplastic composites is developed. The model takes into account a stainless steel mesh heating element located at the interface of the two composite adherends to be welded. This heating element serves to localize the heating where it is needed most, i.e. at the weld interface. The magnetic, electrical, and thermal properties of the carbon fiber/polyphenylene sulfide composite and other materials are identified experimentally or estimated and implemented in the model. The model predicts the temperature–time curves during the heating of the composite and is used to define processing parameters leading to high-quality welded joints. The effect of the heating element size and input current on the thermal behavior is investigated, both experimentally and using the developed model. The welds quality is assessed through microscopic observations of the weld interfaces, mechanical testing, and observations of the fracture surfaces. A comparison with two other welding processes, namely resistance welding and ultrasonic welding is finally conducted. Keywords Thermoplastic composites, joint/joining, finite element analysis, welding Introduction already begun to use welding as an assembly method for parts made of thermoplastic composites. For exam- Joining is inevitable in the design of large and complex ple, the leading edges of the wings of the Airbus A340- composite structures. Structures made of thermosetting 600 and A380 are assembled by resistance welding composites rely mainly on two joining processes: adhe- (RW), and the empennage of the Gulfstream G650 is sive bonding and mechanical fastening. Both of these assembled by induction welding (IW).1 Another weld- processes come with a number of disadvantages such as ing process that shows potential to be used at large a high sensitivity to surface preparation and long curing scale is ultrasonic welding (UW).2 times for adhesive bonding as well as delamination and In the RW process, an electrically conductive heat- stress concentrations due to holes drilling for mechan- ing element (HE) connected to a power supply is placed ical fastening. These two joining processes can be avoided when a structure is made of thermoplastic 1Department of Mechanical Engineering, E´cole de technologie supe´rieure, composites. In effect, thermoplastic composites offer Montre´al, Que´bec, Canada the possibility to be assembled by welding. Welding 2Department of Structural Integrity and Composites, Delft University of consists in heating a thermoplastic composite over its Technology, Delft, The Netherlands glass transition (amorphous polymer) or melting (semi- crystalline polymer) temperature and allowing it to cool Corresponding author: Martine Dube´, Department of Mechanical Engineering, E´cole de tech- down under the application of pressure. It is a fast pro- nologie supe´rieure, 1100 Notre-Dame Street West, Montre´al, Que´bec, cess, of the order of seconds, and is not sensitive to Canada, H3C 1K3. surface preparation. The aerospace industry has Email: [email protected] 2896 Journal of Composite Materials 50(21) at the interface of two thermoplastic composite parts to UD fiber-based adherends helps generate and concen- be welded (adherends). An electrical current is applied trate the heat at the weld interface. With the develop- to the HE which heats up by Joule effect. The polymer ment of new manufacturing methods such as located in the vicinity of the HE softens or melts and automated fiber placement, UD fiber reinforcement is when the current is stopped, the assembly cools down, more and more popular. UD reinforcement also pro- under the application of pressure, to form a welded vides the composite with high strength and stiffness, joint. Carbon fiber fabrics were historically used as making these materials ideal candidates for many aero- HE; however, in the past years, it was shown that HE space applications. As Bayerl et al.6 and Ahmed et al.7 in the form of stainless steel meshes of various sizes reported, very few studies have focused on thermoplas- offer a better process control and a more uniform tem- tic composites IW based on a HE. Therefore, a study perature over the weld area.3 UW is a process in which on welding of UD carbon fiber thermoplastic compos- low amplitude and high-frequency vibrations, in the ites with an HE is needed and relevant. Furthermore, range of kHz, are transmitted to the thermoplastic although such an HE is a foreign material that one may composite adherends by a sonotrode. As opposed to want to avoid, it was shown in studies on RW that it the RW process, heat is generated by surface and inter- does not affect the weld mechanical performance in a molecular friction which occurs due to the high-fre- negative way. Even under fatigue loading, good mech- quency vibrations. Energy directors, i.e. man-made anical performance was reported for joints made by neat polymer protrusions located at the weld interface, RW with a stainless steel mesh HE.8 are used to localize the heating at the weld line. The first numerical works about induction heating of Historically, energy directors were made of rectangular composites were dedicated to the identification of the or triangular shapes. Recently, Villegas4 successfully dominant heating mechanisms. Many authors claimed used flat energy directors to weld thermoplastic com- that Joule heating within the carbon fibers is mainly posite adherends which facilitated the process control. responsible for the temperature increase,9–19 while IW is based on a high-frequency alternating elec- others20–23 believed that heating occurs at the fiber trical current circulating in a coil. The coil generates a junctions. This last heating mechanism relies on dielec- time-variable magnetic field (MF) of the same fre- tric heating or Joule losses caused by contact resistance quency as the current. If an electrical conductor is at fiber junctions. Yarlagadda et al.22 developed a placed in the vicinity of the MF, eddy currents are model that identified the dominant heating mechanism induced, leading to heat generation by Joule losses. as a function of the dielectric junction impedance, fiber This principle is used to weld thermoplastic composites. resistivity, and contact resistance. In all cases, losses at Here again, an electrically conductive HE is placed junctions were dominant over fiber heating unless the between the two adherends. An electrical current is contact resistance between the fibers was very low. On applied to the coil until the polymer located close to the other side, Mitschang et al.11 demonstrated that the HE softens or melts. The current is then stopped, carbon fiber with or without resin heated up equally, allowing the polymer to cool down under the applica- meaning that dielectric heating would be less important tion of pressure. Similarly to the RW process, the HE than fiber Joule heating and contact resistance at junc- remains trapped in the weld after the welding oper- tions. It is interesting to mention that the methodology ation. The HE may consist in a stainless steel mesh of for the measurement of the electrical resistance of the various dimensions or a magnetic susceptor. adherend proposed by Rudolf et al.,24 which was also Alternatively, if the adherends are made of carbon used by Mitschang et al.,11 takes into account both the fiber fabric, no HE is necessary as the fiber architecture fiber resistance and the junction resistance. Thus, by allows for current close loops to exist. These loops may using such a measurement as an input value, fiber be sufficient to generate heat without having to add any Joule losses and junction Joule losses were implicitly foreign material to the weld stack. However, in such a included in the models. Finally, it should be noted case, heat would be concentrated at the surface of the that the heating mechanism depends on several param- top adherend, i.e. the adherend located closest to the eters such as the material type (consolidated or non- coil. Heat then propagates through the thickness of the consolidated plies), fiber architecture (fabric or UD) adherend until it reaches the location where it is needed, and lay-up, matrix, and induction heating process par- i.e.
Load more

Recommended publications
  • Welding Process Reference Guide
    Welding Process Reference Guide gas arc welding…………………..GMAW -pulsed arc…………….……….GMAW-P atomic hydrogen welding……..AHW -short circuiting arc………..GMAW-S bare metal arc welding…………BMAW gas tungsten arc welding…….GTAW carbon arc welding……………….CAW -pulsed arc……………………….GTAW-P -gas……………………………………CAW-G plasma arc welding……………..PAW -shielded……………………………CAW-S shielded metal arc welding….SMAW -twin………………………………….CAW-T stud arc welding………………….SW electrogas welding……………….EGW submerged arc welding……….SAW Flux cord arc welding…………..FCAW -series………………………..…….SAW-S coextrusion welding……………...CEW Arc brazing……………………………..AB cold welding…………………………..CW Block brazing………………………….BB diffusion welding……………………DFW Diffusion brazing…………………….DFB explosion welding………………….EXW Dip brazing……………………………..DB forge welding…………………………FOW Flow brazing…………………………….FLB friction welding………………………FRW Furnace brazing……………………… FB hot pressure welding…………….HPW SOLID ARC Induction brazing…………………….IB STATE BRAZING WELDING Infrared brazing……………………….IRB roll welding…………………………….ROW WELDING (8) ultrasonic welding………………….USW (SSW) (AW) Resistance brazing…………………..RB Torch brazing……………………………TB Twin carbon arc brazing…………..TCAB dip soldering…………………………DS furnace soldering………………….FS WELDING OTHER electron beam welding………….EBW induction soldering……………….IS SOLDERING PROCESS WELDNG -high vacuum…………………….EBW-HV infrared soldering…………………IRS (S) -medium vacuum………………EBW-MV iron soldering……………………….INS -non-vacuum…………………….EBW-NV resistance soldering…………….RS electroslag welding……………….ESW torch soldering……………………..TS
    [Show full text]
  • Estimation of Weld Quality in High-Frequency Electric Resistance Welding with Image Processing
    Kim March 2007 LAYOUT:Layout 1 2/8/07 2:30 PM Page 71 WELDING RESEARCH Estimation of Weld Quality in High-Frequency Electric Resistance Welding with Image Processing An image analysis algorithm can estimate the weld quality by using the weld image data during high-frequency electric resistance welding BY D. KIM, T. KIM, Y. W. PARK, K. SUNG, M. KANG, C. KIM, C. LEE, AND S. RHEE ABSTRACT. In high-frequency electric duction welding method, an induction coil surface is compressed by the squeeze resistance welding (HF-ERW), the weld is used in inducing high-frequency current roller, excreting oxided material from the quality is determined by the welding phe- to generate heat. In high-frequency resis- melting surface to generate a weld. The nomenon in the welding spot proximity. tance welding, on the contrary, a contac- molten part of the pipe generated by the Methods to eliminate or minimize defects, tor is applied to the workpiece to directly resistance heat contains oxided material therefore, include real-time monitoring of provide the current (Ref. 1). High- on account of exposure to the air. There- the weld quality and problem solving as frequency induction welding is primarily fore, if the oxided material is not com- problems arise. It is possible to estimate used in joining small-diameter steel pipes, pletely excreted during compression, and weld quality qualitatively by using the weld while HF-ERW is used in joining large- oxided material remains in the welding image data during HF-ERW. A method to diameter steel pipes. part as an impurity, the weld quality be- predict the weld quality using image pro- The characteristic of HF-ERW is the re- comes degraded.
    [Show full text]
  • Can We Use Induction Heating to Weld Steel As a Fusion Welding Process?
    International Journal of Scientific Engineering and Research (IJSER) ISSN (Online): 2347-3878 Index Copernicus Value (2015): 62.86 | Impact Factor (2015): 3.791 Can We Use Induction Heating to Weld Steel as a Fusion Welding Process? Hani A. Almubarak1, Abdulaziz I. Albannai2 Abstract: Using heat is very important for forming, joining, or treating most metals. Heat can be applied to metal by different processes, such as flame, ARC, friction, furnaces, and induction heating. This paper will focus on induction heating process, how it works, its advantages, applications, and if it can be used for welding steel as a fusion welding process? Using some sources is significant to buildup our point of view in this paper about using induction heating process for welding a steel as fusion welding. Keywords: Induction heating, steel, welding, and fusion 1. Introduction In the next figure (2),it is showing the “Eddy Currents” (black arrows in work-piece) flow against the electrical Induction heating uses high frequency electricity to heat resistivity of the metal work-piece. Without any direct electrically conductive materials (usually a metal). Eddy contact between the metal part and the inductor, this currents are generated within the metal where the metal generates a localized and precise heat .Both magnetic and resistance leads to its heating. This is done by the effect of non-magnetic parts can be heated in this way. This effect is the electromagnetic induction. The heat is generated inside related to the "Joule effect", a scientific formula expressing the work-piece, which is very efficient and a non-contact the relationship between heat produced by electrical current process.
    [Show full text]
  • Induction Weld Seam Characterization of Continuously Roll Formed TRIP690 Tubes
    metals Article Induction Weld Seam Characterization of Continuously Roll Formed TRIP690 Tubes Alexander Bardelcik * and Bharathwaj Thirumalai Ananthapillai School of Engineering, College of Engineering and Physical Sciences, University of Guelph, Guelph, ON N1G 2W1, Canada; [email protected] * Correspondence: [email protected]; Tel.: +1-519-824-4120 Received: 5 March 2020; Accepted: 20 March 2020; Published: 25 March 2020 Abstract: The weld seam characteristics of continuously roll formed and induction seam welded TRIP690 tubes were examined in this work. These tube are subsequently used in automotive hydroforming applications, where the weld seam characteristics are critical. The induction seam welds are created through a solid-state welding process and it was shown that by increasing the induction frequency by 26%, the weld seam width within the heat affected zone (HAZ) reduced due to a plateau in the hardness distribution which was a result of a delay in the transformation of martensite. 2D hardness distribution contours were also created to show that some of the weld conditions examined in this work resulted in a strong asymmetric hardness distribution throughout the weld, which may be undesirable from a performance perspective. An increase in the pressure roll force was also examined and revealed that a wider total weld seam width was produced likely due to an increase in temperature which resulted in more austenitization of the sheet edge prior to welding. The ring hoop tension test (RHTT) was applied to the tube sections created in this work. A Tensile and Notch style ring specimen were tested and revealed excellent performance for these welds due to high peak loads (~17.2 kN) for the Notch specimens (force deformation within weld) and lower peak loads (~15.2 kN) for the Tensile specimens for which fracture occurred in the base metal.
    [Show full text]
  • Analysis of Induction Heating System for High Frequency Welding 
    FACTA UNIVERSITATIS Ser: Elec. Energ. Vol. 25, No 3, December 2012, pp. 183 - 191 DOI: 10.2298/FUEE1203183I ANALYSIS OF INDUCTION HEATING SYSTEM FOR HIGH FREQUENCY WELDING Ilona Iatcheva, Georgi Gigov, Georgi Kunov, Rumena Stancheva Technical University of Sofia, Bulgaria Abstract. The aim of the work is the investigation of induction heating system used for longitudinal, high frequency pipe welding.Coupled electromagnetic and temperature field distribution has been studied in order to estimate system efficiency and factors influencing the quality of the welding process and required energy. The problem was considered as three dimensional. Time harmonic electromagnetic and transient thermal field has been solved using finite element method and COMSOL 4.2 software package. Key words: induction heating, high frequency welding, 3D analysis, finite element method, coupled field problem 1. INTRODUCTION Technologies based on induction heating are widely used in industry due to their advantages: high energy efficiency, excellent product quality, very good accuracy in heating of certain zones in a short time, clean operating conditions [1]-[3]. Induction heating has a great variety of industrial applications [4]: induction hardening, induction tempering, induction brazing, induction bonding, induction welding, induction annealing, induction pre and post-heating, induction forging, induction melting, induction straight- ening, induction plasma production, etc. The object of the study in this investigation is an induction heating system, used for high frequency longitudinal pipe welding. The aim of the research and motivation for car- rying out the work is the necessity of development, analyzing and estimating of the system. The main task is to define and then to determine optimal factors and parameters influencing the welding process quality and required energy.
    [Show full text]
  • Induction Welding of High Performance Thermoplastic Composites
    Induction welding of high performance thermoplastic composites Focused heat generation in weld zones of carbon fiber laminates by magnetic field manipulation and carbon fiber susceptors M.C. Dhondt Student no: 4274318 Induction welding of high performance thermoplastic composites Focused heat generation in weld zones of carbon fiber laminates by magnetic field manipulation and carbon fiber susceptors by M.C. Dhondt to obtain the degree of Master of Science at the Delft University of Technology, Student number: 4274318 Project duration: February 18, 2019 – December 20, 2019 Thesis committee: Dr.-Ing. Jan Stüve, TU Delft Prof. C.A. Dransfeld, TU Delft Dr.ing. S. Giovani Pereira Castro, TU Delft M.Sc. Niklas Menke DLR Preface Before you lies the dissertation “Induction welding of high performance thermoplastic com- posites: focused heat generation in weld zones of carbon fiber laminates by magnetic field manipulation and carbon fiber susceptors”. It has been written to obtain a master’s degree in Aerospace Structures and Materials from the Delft University of Technology. The thesis was sponsored by and executed at the German Aerospace Center (DLR) in Stade, Germany. This report is written for anybody interested in induction welding of thermoplastic composites with some background knowledge on composites. It can be read to gain knowledge on the principles of induction welding of thermoplastic composites, to get familiarized with its current state of the art, to get to know about the influence the magnetic field direction has on the heating of multidirectional laminates, to learn about what carbon fiber material heats up more than average and whether this can be used as a benefit in induction welding.
    [Show full text]
  • Introduction to Welding Engineering
    1 Introduction to Welding Engineering 1.1. History and Development of Welding The first historical reference about welding is given in Bible and Tubal-Cain was the first smith who forged the instruments of bronze and iron. About 5000 years back the forge, hammer, anvil, bellows and fire heaters were used for forging. It was in the year 1887 that Thomas Fletcher of Warrington invented various blow pipes for burning hydrogen or coal gas with air or oxygen. The bicycle frames were manufactured with the help of these blow pipes. This type of blow pipe is used even today where acetylene gas is used in place of hydrogen or coal gas. In 1892, acetylene gas was first discovered by Thomas Leopold Wilson of North Carolina. In 1886, two Frenchmen, the Brins brothers formed a company for the liquefaction of air from which pure oxygen was obtained. The only acetylene welding blow pipe was invented by Fouche and Picard. Volta, after whom the term volt is named, demonstrated in 1800 that the electric arc could be used for melting iron wire and the process of fusion of metals by electricity was born. A swedish marine engineer thought of protecting the arc with an inert gas. This gas, he produced by applying a flux to the electrode. The flux melts and vaporises in the intense heat of the welding arc, protects the molten metal from the air and can be used to add alloying elements to the welding wire. Many advances have been made since these early days. Auto- mation has added to them, welding arcs and cutting flames, electronically guided arc, gas combined with electricity in hydrogen, helium and argon arcs.
    [Show full text]
  • Welding Thermoplastic Composites
    Welding thermoplastic composites Multiple methods advance toward faster robotic welds using new technology for increased volumes and larger aerostructures. By Ginger Gardiner / Senior Editor » Unlike composites made with a thermoset matrix, thermoplastic composites (TPCs) require neither complex chemical reactions nor lengthy curing processes. Thermoplastic prepregs require no refrig- eration, offering practically infinite shelf life. The polymers used in aerospace TPCs — polyphenylene sulfide (PPS), polyetherimide (PEI), polyetheretherketone (PEEK), polyetherketoneketone (PEKK) and polyarylketone (PAEK) — offer high damage toler- ance in finished parts, as well as moisture and chemical resistance and, thus, do not degrade in hot/wet conditions. And they can be remelted, promising benefits in repair and end-of-life recyclability. But perhaps the greatest driver for TPC use in developing aircraft is the ability to join components via fusion bonding/welding. It Induction welded window frame for TPC fuselage presents an attractive alternative to the conventional methods — This compression molded short CF/PPS reinforcement ring, induction welded to mechanical fastening and adhesive bonding — used to join ther- a TenCate CF/PPS CETEX skin by KVE Composites (Den Haag, The Netherlands), moset composite (TSC) parts. demonstrates how window frames could be assembled in future TPC airframes. As defined in the widely cited paper, “Fusion Bonding/Welding Source | KVE Composites / Photo | Ginger Gardiner 50 SEPTEMBER 2018 CompositesWorld Welding ThermoplasticsNEWS FIG. 1 Advanced Thermoplastic Composite Welding Technologies of Thermoplastic Composites,” by Ali Yousefpour, National Resistance welding Research Council Canada (Ottawa, ON, Canada), “The process of Along with KVE Composites Group (The Hague, The Nether- fusion-bonding involves heating and melting the polymer on the lands), GKN Fokker is an acknowledged leader in TPC welding bond surfaces of the components and then pressing these surfaces development (see Learn More, p.
    [Show full text]
  • Principles of High Frequency Induction Tube Welding
    PRINCIPLES of INDUCTION TUBE WELDING PRINCIPLES OF HIGH FREQUENCY INDUCTION TUBE WELDING By JOHN WRIGHT Electronic Heating Equipment, Inc. Sumner, Washington Page 1 © 1997 Electronic Heating Equipment, Inc. Page 1 PRINCIPLES of INDUCTION TUBE WELDING Introduction and it is inductance rather than resistance that governs current flow at high frequencies. This is High Frequency induction welding accounts for the sometimes refered to as “proximity effect”. majority of welded tubing produced worldwide, yet it is still a largely misunderstood process. Part of the It can be seen from this that there are two main reason is that the process is very forgiving, however a paths along which current can flow when a voltage is thorough understanding of it can lead to higher applied or induced across the edges of the strip. The product yields and quality. key to operating a high frequency welder efficiently is to direct the majority of the current along the faying Principals of operation edges where it does useful work in heating them, and minimise the wasteful parasitic current that flows around the inside surface of the tube.This is done by Induction welding is a form of Electrical Resistance making the impedance of the vee low relative to that Welding (ERW) in which the large rotary trans- of the I.D. surface. former common in low frequency ERW is replaced by a “virtual transformer” consisting of the work coil Function of impeder (primary winding) and the tube itself (secondary winding). A ferromagnetic core inside the tube has a similar role to the laminated iron core in a conven- The first tool we have is called an impeder because it tional transformer.
    [Show full text]
  • INDUCTION DIVERSITY Elotherm and IAS Overview SMS GROUP Leaders in Plant Construction and Machine Engineering
    INDUCTION DIVERSITY Elotherm and IAS overview SMS GROUP Leaders in plant construction and machine engineering The name SMS group stands for tailor-made metallurgical plants, machinery, and services. Applying innovative ideas and globally uniform standards, we join forces with our customers in the steel and NF metals industries to create all-new products – with pinpoint precision. COMBINED FORCES, WE TRANSFORM ... WORLDWIDE EFFICIENCY THE WORLD OF METALS SMS group is one of the leading global system The plants, machines and services of SMS group suppliers of plants, machines and services along provide its customers along the metallurgical process the entire metallurgical value chain. With a strong chain with outstanding solutions which help shape workforce of about 14,000 employees, we are able the global community. to present our customers with unique solutions, both technically and economically remarkable, to over- come any challenge. In our complex world, safe and convenient infrastruc- tures demand solutions in which steel, aluminum, and NF metals can demonstrate their wide range of applications. 2 SMS ELOTHERM AND IAS Your partners for induction heating solutions With its developments and system solutions, Elotherm and IAS have set standards in induction technology for decades. The medium-sized interna- tionally operating companies are part of the SMS group. As technology leaders, Elotherm and IAS combine all competences when it comes to induction. ■ Induction heating of metals for forging, rolling and extruding ■ Induction hardening and quench & temper ■ Induction welding, annealing and special technology for tubes ■ Continuous induction strip heating ■ Induction kinetics ■ Induction melting CUSTOMIZED SYSTEMATIC SOLUTIONS Elotherm’s and IAS’ technology is based on compatible modular plant components, which can be efficiently combined into individual configurations.
    [Show full text]
  • A Comparative Study of Arc Welding and Resistance Welding Processes
    November 2017, Volume 4, Issue 11 JETIR (ISSN-2349-5162) A COMPARATIVE STUDY OF ARC WELDING AND RESISTANCE WELDING PROCESSES 1Dr. Kailash Chaudhary Professor Department of Mechanical Engineering Raj Engineering College Jodhpur, India Abstract: This paper makes an in-depth comparative study of arc welding and resistance welding processes. The objective is to present the current challenges and future aspects of these welding processes and their usefulness as fabrication technology. The importan t considerations and application areas of both the techniques are discussed in this paper. 1INTRODUCTION The American Welding Society (AWS) defines welding as “a materials joining process which produces coalescence of materials by heating them to suitable temperatures with or without the application of pressure or by the application of pressure alone and with or with out the use of filler material" [1]. Mechanical parts are often highly complicated in design or large in size. Manufacturing a unit of such a part as a single ent ity is not always possible. However, it can be produced in the form of different components or structures and could be joined by several joining processes to get the complete unit or assembly. It is here that welding has been found the most useful fabrication technology in joining diffe rent components and synthesizing them into a whole system. 2ARC WELDING PROCESS ES One of the most popular and common types of welding in use today is arc welding. It uses an electric arc as the source of hea t to melt and join metals. The arc is formed between the metal being worked on and an electrode connected to the arc welder.
    [Show full text]
  • Radio Frequency Induction Welding of Silver Nanowire Networks for Transparent Heat Films
    materials Article Radio Frequency Induction Welding of Silver Nanowire Networks for Transparent Heat Films Jisoo Oh 1,†, Long Wen 1,†, Hyunwoo Tak 1, Heeju Kim 1 , Gyowun Kim 1, Jongwoo Hong 1 , Wonjun Chang 1 , Dongwoo Kim 1 and Geunyoung Yeom 1,2,* 1 School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon 16419, Korea; [email protected] (J.O.); [email protected] (L.W.); [email protected] (H.T.); [email protected] (H.K.); [email protected] (G.K.); [email protected] (J.H.); [email protected] (W.C.); [email protected] (D.K.) 2 SKKU Advanced Institute of Nano Technology (SAINT), Sungkyunkwan University, Suwon 16419, Korea * Correspondence: [email protected] † Both authors contributed equally to this work. Abstract: Transparent heat films (THFs) are attracting increasing attention for their usefulness in various applications, such as vehicle windows, outdoor displays, and biosensors. In this study, the effects of induction power and radio frequency on the welding characteristics of silver nanowires (Ag NWs) and Ag NW-based THFs were investigated. The results showed that higher induction frequency and higher power increased the welding of the Ag NWs through the nano-welding at the junctions of the Ag NWs, which produced lower sheet resistance, and improved the adhesion of the Ag NWs. Using the inductive welding condition of 800 kHz and 6 kW for 60 s, 100 ohm/sq of Ag NW thin film with 95% transmittance at 550 nm after induction heating could be decreased to 56.13 ohm/sq, without decreasing the optical transmittance. In addition, induction welding of the Ag NW-based THFs improved haziness, increased bending resistance, enabled higher operating Citation: Oh, J.; Wen, L.; Tak, H.; Kim, H.; Kim, G.; Hong, J.; Chang, W.; temperature at a given voltage, and improved stability.
    [Show full text]