scholarly journals Joining of Thermoplastic Composites with Metals Using Resistance Element Welding

2020 ◽  
Vol 10 (20) ◽  
pp. 7251 ◽  
Author(s):  
Juliane Troschitz ◽  
Julian Vorderbrüggen ◽  
Robert Kupfer ◽  
Maik Gude ◽  
Gerson Meschut
Keyword(s):  
Welding Process ◽  
Thermoplastic Composites ◽  
Innovative Technology ◽  
Welding Parameters ◽  
Compression Moulding ◽  
Steel Sheets ◽  
Lap Shear ◽  
Before And After ◽  
Resistance Element Welding ◽  
Glass Fibre Reinforced

Joining is a key enabler for a successful application of thermoplastic composites (TPC) in future multi-material systems. To use joining technologies, such as resistance welding for composite-metal joints, auxiliary joining elements (weld inserts) can be integrated into the composite and used as an interface. The authors pursue the approach of embedding metal weld inserts in TPC during compression moulding without fibre damage. The technology is based on the concept of moulding holes by a pin and simultaneously placing the weld insert in the moulded hole. Subsequently, the composite component can be joined with metal structures using conventional spot welding guns. For this purpose, two different types of weld inserts were embedded in glass fibre reinforced polypropylene sheets and then welded to steel sheets. A simulation of the welding process determined suitable welding parameters. The quality of the joints was analysed by microsections before and after the welding process. In addition, the joint strength was evaluated by chisel tests as well as single-lap shear tests for the different weld insert designs. It could be shown that high-quality joints can be achieved by using the innovative technology and that the load-bearing capacity is significantly influenced by the weld inserts head design.

scholarly journals Multi-Objective Optimization of Resistance Welding Process of GF/PP Composites

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2560
Author(s):  
Guowei Zhang ◽  
Ting Lin ◽  
Ling Luo ◽  
Boming Zhang ◽  
Yuao Qu ◽  
...  
Keyword(s):  
Signal To Noise Ratio ◽  
Welding Process ◽  
Welding Current ◽  
Resistance Welding ◽  
Thermoplastic Composites ◽  
Current Time ◽  
Process Factor ◽  
Welding Equipment ◽  
Lap Shear ◽  
Adhesive Connections

Thermoplastic composites (TPCs) are promising materials for aerospace, transportation, shipbuilding, and civil use owing to their lightweight, rapid prototyping, reprocessing, and environmental recycling advantages. The connection assemblies of TPCs components are crucial to their application; compared with traditional mechanical joints and adhesive connections, fusion connections are more promising, particularly resistance welding. This study aims to investigate the effects of process control parameters, including welding current, time, and pressure, for optimization of resistance welding based on glass fiber-reinforced polypropylene (GF/PP) TPCs and a stainless-steel mesh heating element. A self-designed resistance-welding equipment suitable for the resistance welding process of GF/PP TPCs was manufactured. GF/PP laminates are fabricated using a hot press, and their mechanical properties were evaluated. The resistance distribution of the heating elements was assessed to conform with a normal distribution. Tensile shear experiments were designed and conducted using the Taguchi method to evaluate and predict process factor effects on the lap shear strength (LSS) of GF/PP based on signal-to-noise ratio (S/N) and analysis of variance. The results show that current is the main factor affecting resistance welding quality. The optimal process parameters are a current of 12.5 A, pressure of 2.5 MPa, and time of 540 s. The experimental LSS under the optimized parameters is 12.186 MPa, which has a 6.76% error compared with the result predicted based on the S/N.

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.

scholarly journals Study of Laser Welding of HCT600X Dual Phase Steels

2014 ◽  
Vol 22 (1) ◽  
pp. 93-98
Author(s):  
Pavol Švec ◽  
Viliam Hrnčiar ◽  
Alexander Schrek
Keyword(s):  
Tensile Strength ◽  
Base Metal ◽  
Heat Affected Zone ◽  
Welding Speed ◽  
Welding Process ◽  
Beam Power ◽  
Welding Parameters ◽  
Dual Phase ◽  
Welded Steel ◽  
Steel Sheets

AbstractThe effects of beam power and welding speed on microstructure, microhardnes and tensile strength of HCT600X laser welded steel sheets were evaluated. The welding parameters influenced both the width and the microstructure of the fusion zone and heat affected zone. The welding process has no effect on tensile strength of joints which achieved the strength of base metal and all joints fractured in the base metal.

MIG-Welding of Dissimilar Advanced High Strength Steel Sheets

2017 ◽  
Vol 885 ◽  
pp. 80-85 ◽  
Author(s):  
Eszter Kalácska ◽  
Kornél Májlinger ◽  
Enikő Réka Fábián ◽  
Pasquale Russo Spena
Keyword(s):  
Automobile Industry ◽  
Welding Process ◽  
High Strength Steels ◽  
High Strength ◽  
Tensile Specimen ◽  
Dissimilar Welding ◽  
Welding Parameters ◽  
Mig Welding ◽  
Advanced High Strength Steels ◽  
Steel Sheets

The need for steel materials with increasing strength is constantly growing. The main application of such advanced high strength steels (AHSS) is the automobile industry, therefore the welding process of different types of AHSSs in dissimilar welding joint was investigated. To simulate the mass production of thin steel sheet constructions (such as car bodies) automated metal inert gas (MIG) welding process was used to weld the TWIP (twinning induced plasticity) and TRIP (transformation induced plasticity) steel sheets together. The welding parameters were successfully optimized for butt welded joints. The joints were investigated by visual examination, tensile testing, quantitative metallography and hardness measurements. The TRIP steel side of the joints showed increased microhardness up to (450-500 HV0.1) through increased fraction of bainite and martensite. Macroscopically the tensile specimen showed ductile behaviour, they broke in the austenitic weld material.

Multi Response Optimization of Spot Welding Process Parameters by Taguchi Method

2020 ◽  
Vol 12 (1) ◽  
Author(s):  
S.P. Sundar Singh Sivam ◽  
A. Thirugnanam ◽  
K. Saravanan ◽  
D. Kumaran ◽  
M. Suresh
Keyword(s):  
Electrical Resistance ◽  
Resistance Spot Welding ◽  
Spot Welding ◽  
Weld Zone ◽  
Welding Process ◽  
Class Ii ◽  
Welding Parameter ◽  
Welding Parameters ◽  
Resistance Spot ◽  
Steel Sheets

Electrode deterioration by deformation and chemical reaction during resistance spot welding of steel sheets confirming to AISI1020 is an issue for class II electrode. In view of this, the present study carried out the impacts of squeeze, weld, current and pressure on the nugget diameter, height, force and waviness of welding joint in electrical resistance spot welding of 0.8mm and 1.5 mm thickness of steel sheets with class II electrode to achieve the benefits of cost saving and quality products. A timer and current controlled electrical resistance spot welding machine having 120 kVA capacities were used. During welding process, current periods of 5, 10, 15, 20 and 25 were selected and it was adjusted by increasing from 8 to 10 kA. The optimum welding parameter for multi objectives was obtained using multi signal to noise ratio and the significant level of the welding parameters was further analysed by analysis of variance for all responses. Based on the confirmation test results, it is found out that the developed model can be effectively used to predict the size of weld zone which can improve the welding quality and performance in GRA. The details of welded joint generated by class II electrode were measured and results were analysed in detail.

Modelling resistance welding of thermoplastic composites with a nanocomposite heating element

2020 ◽  
pp. 002199832095705
Author(s):  
David Brassard ◽  
Martine Dubé ◽  
Jason R Tavares
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Welding Process ◽  
Element Model ◽  
Resistance Welding ◽  
Thermoplastic Composites ◽  
Process Window ◽  
Cohesive Failure ◽  
Electrically Conductive ◽  
Lap Shear

Electrically conductive nanocomposite heating elements are being developed as a complement to traditional carbon fibre or stainless steel heating elements in resistance welding of thermoplastic composites. Here we present the development of a finite element model of the resistance welding process with these new heating elements, from which we establish a process window for high quality welded joints. The finite element model results were validated experimentally and a lap shear strength improvement of 28% is reported relative to previously published results. Fractography analysis of the broken joints revealed a thin-layer cohesive failure mode due to the brittleness of the nanocomposite heating elements.

Ultrasonic plastic welding of CF/PA6 composites to aluminium: Process and mechanical performance of welded joints

2019 ◽  
Vol 53 (18) ◽  
pp. 2607-2621 ◽  
Author(s):  
Umberto F Dal Conte ◽  
Irene F Villegas ◽  
Julien Tachon
Keyword(s):  
Mechanical Performance ◽  
Lightweight Design ◽  
Welding Process ◽  
Thermoplastic Composites ◽  
Process Time ◽  
Reinforced Plastics ◽  
Lap Shear ◽  
Physical Treatments ◽  
Reinforced Thermoplastics ◽  
Plastic Welding

Due to environmental challenges and need for action with regard to CO2 emission, reducing the weight of vehicles has become one of the most important goals of car manufacturers in Europe. Materials like fibre-reinforced plastics and aluminium are the core of the research for lightweight design. However, efficiently joining these materials together is still a challenge. When thermoplastic composites are used, direct joining (i.e. without adhesives or fasteners) with the metal substrate can be obtained using welding technologies which melt the thermoplastic at the interface. In this study, ultrasonic plastic welding was investigated as a candidate technology for joining aluminium and carbon fibre-reinforced thermoplastics. The goal was to understand the main mechanisms involved in the welding process and how they affect the performance of the joint. Initially, the technique proved to be successful, but moderate strengths were obtained. Therefore, several surface pre-treatments of aluminium were analysed to improve the performance in terms of lap shear strength; mechanical, chemical and physical treatments were also carried out. With laser structuring, strengths comparable to adhesive bonded joints were obtained, but in a much shorter process time. Other treatments led to considerable improvements as well. The encouraging results achieved represent an important step in the development of ultrasonic plastic welding for multi-material joining in the automotive industry.

Microstructure and Mechanical Performance of Cold Metal Transfer Spot Joints of AA6061-T6 to Galvanized DP590 Using Edge Plug Welding Mode

2016 ◽  
Vol 138 (7) ◽  
Author(s):  
Haiyang Lei ◽  
Yongbing Li ◽  
Blair E. Carlson ◽  
Zhongqin Lin
Keyword(s):  
Mechanical Performance ◽  
Welding Process ◽  
Metal Transfer ◽  
Weld Nugget ◽  
Weld Strength ◽  
Welding Parameters ◽  
Feed Speed ◽  
Cold Metal Transfer ◽  
Lap Shear ◽  
Cold Metal

Dissimilar joining of aluminum to steel poses a challenge for arc welding. In this study, aluminum AA6061-T6 and hot dipped galvanized DP590 steel were joined using the Fronius cold metal transfer (CMT) welding process applying an edge plug welding mode (EPW). The correlation of the welding parameters, weld characteristics, and weld strength was systematically investigated. It was found that the EPW mode created a zinc-rich zone at the weld root along the Al–steel faying interface which transitioned to a continuous and compact intermetallic compounds (IMC) layer in the middle portion of the joint. The fracture propagation in lap-shear specimens was affected by this increase of IMC layer thickness. At a wire feed speed (wfs) of 5.6 m/min, the fracture initiated along the zinc-rich layer at the faying interface and then, upon meeting the compact IMC layer, propagated into the aluminum weld nugget. Propagation followed a path within the weld nugget along the boundary between columnar and equiaxed grains leading to weld nugget pullout upon fracture. For IMC layer peak thicknesses below 10 μm, the strength increased as a function of weld nugget diameter. However, larger heat inputs resulted in IMC layer thicknesses greater than 10 μm and interfacial fracture.

scholarly journals Development of the Oxyacetylene Welding Process for PEI/Glass Fiber Laminates

2021 ◽  
Vol 100 (4) ◽  
pp. 142-149
Author(s):  
VITÓRIA SIMPLÍCIO OLIVEIRA ◽  
◽  
RAFAEL RESENDE LUCAS ◽  
TAYENNE PRADO CARVALHO ◽  
LUIS FELIPE MARQUES ◽  
...  
Keyword(s):  
Composite Materials ◽  
Glass Fiber ◽  
Mechanical Test ◽  
Fiber Composite ◽  
Low Cost ◽  
Welding Process ◽  
Cost Savings ◽  
Polymeric Materials ◽  
Welding Parameters ◽  
Lap Shear

The technology for joining thermoplastics through welding offers numerous advantages over mechanical joining. Currently, the joining of composite parts with weight reduction and cost savings is being developed to improve aircraft performance. This paper proposes the use of oxygen-acetylene as a process for bonding composite materials. Oxyacetylene welding is a simple and economical method that can be suitable for polymeric materials. The advantage of applying this technique is a more accessible process that is composed of a portable system with low cost. In evaluating the welding efficiency for composite materials, the lap shear strength (LSS) mechanical test stands out among the most referenced essays in the literature. This work aimed to study the development of oxyacetylene flame welding as well as the optimization of welding parameters for polyetherimide/glass fiber composite. The optimization was performed using complete factorial planning 22 as a tool, and the variables studied were time and distance of the flame. With the optimized condition set as the response variable with the highest lap shear value, the joints obtained were measured for their quality by means of end-notched flexure mechanical testing, thermal analysis, and fracture analysis after LSS testing using optical and electronic microscopy.

scholarly journals Spot Welding of 6061 Aluminum Alloy by Friction Stir Spot Welding Process

2017 ◽  
Vol 7 (3) ◽  
pp. 1629-1632 ◽  
Author(s):  
M. A. Tashkandi ◽  
J. A. Al-jarrah ◽  
M. Ibrahim
Keyword(s):  
Welded Joints ◽  
Spot Welding ◽  
Shear Fracture ◽  
Welding Process ◽  
Friction Stir Spot Welding ◽  
Fracture Load ◽  
Welding Parameters ◽  
Friction Stir ◽  
Pull Out ◽  
Lap Shear

This study was focused on the effect of welding parameters on the lap-shear fracture load of the welded joints prepared by friction stir spot welding. Four different weld parameters were analyzed: rotational speed, dwell time, pin length and shoulder size of the welding tool. It was found that the lap-shear fracture load increases with an increase of the welding parameters to a limited value and decreases with further increase. The strong welded joints failed under nugget-pull out fracture.

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