Superconducting Joining Method between REBCO Coated Conductors

<div class="htmlview paragraph">Over the past several decades, significant gains in automobile fuel efficiency have been achieved through down-sizing, aerodynamic design and drive train improvements. As performance limits are approached in these areas, aluminum is being used to further reduce body weight by up to 40% compared to steel. In anticipation of the continued demand for more fuel efficient automobiles, aluminum sheet component unibody and extrusion and cast component space frame designs have been studied to address joining and structural performance. Joint geometries unique to specific body designs clearly illustrate the need for close linkage of the design and assembly functions.</div> <div class="htmlview paragraph">Joining and assembly methods that provide static and dynamic structural integrity, 15 to 20 year durability and that can be integrated into robust manufacturing systems are key to aluminum usage for auto body structure. The applicability of a wide variety of joining methods from the more common resistance spot and arc welding processes to the newer methods of adhesive bonding, magnetic staking and riveting are examined. A review of the technical attributes and issues associated with each method is presented. Comparisons are drawn between the various joining methods on the basis of structural performance, environmental performance, manufacturing issues and economics.</div>

A variety of flip chip technologies are available today which differ in bumping material, substrate type, pad metallization and joining method. They are found in packages as well as on multichip modules and directly flip chip bonded on the board. Components including flip chip like ball grid arrays and chip size packages are introduced. Flip chip is the most favored assembly technology for high frequency applications due to the small parasitic of the short bump interconnect. High performance packages for optoelectronic devices using self-alignment during a fluxless reflow soldering are shown as well as the integration of MMICs. High density multichip modules have been fabricated for large pixel detectors of a nuclear detector with eight Chips and more than 46000 I/Os with an acceptable yield. Flip chip technology is a very flexible assembly method for different applications. Variations of the bump structure can be used for MEMS packaging as well and it was demonstrated by the assembly of a thin membrane to form an absolute pressure sensor with a vacuum enclosure. For different packaging requirements the appropriate technology should be chosen very carefully. An overview will be given for different bumping and flip chip joining methods suitable for high volume production as well as for prototyping. Wafer bumping methods will focus on electroless deposition of nickel/gold as well as on electroplating of gold, SnPb and AuSn solders. For rapid prototyping single chip bumping methods are described. Examples of different joining methods - soldering, adhesive bonding and thermocompression bonding - will be shown.

Modular construction is the off-site fabrication and assembly of building components in a controlled factory environment, offering advantages in terms of time efficiency, quality control, and addressing labour shortages over traditional construction methods. While several studies have evaluated the seismic performance of steel modular buildings, limited studies have evaluated the seismic performance of composite modular buildings (CMBs) that incorporate composite elements, such as concrete-filled steel tubes (CFSTs). Moreover, the promising findings from steel modular buildings highlight the need to evaluate the seismic performance of CMBs, as this would facilitate the expansion of current design Standards to include modular construction. This study investigates the seismic performance of a 10-storey CMB with CFST columns. The methodology included developing a 3D finite element model in OpenSees software using advanced material models and modelling approaches to accurately simulate the nonlinear response. Modal analysis, nonlinear pushover analysis, and nonlinear time history analyses using a selected suite of ground motions were performed. Results indicated that Australian Standards underestimate the fundamental period, ductility, and overstrength of CMBs. The structure demonstrated robust performance, with generally low residual inter-storey drifts, suggesting minimal permanent deformation. The promising seismic performance of mid-rise CMBs with CFST columns in low-to-moderate seismicity suggests their potential safe application in high seismicity regions. • A novel joining method was used for composite modular buildings under earthquake. • Seismic performance of buildings is investigated using OpenSees software. • The joining method can be safely used for modular buildings under earthquake.

The complexity of new body concepts to meet customer demands, clearly calls for the necessity of a concurrent body engineering approach. Outstanding properties can only be reached if the choice of materials, body concept and joining methods is done in an integrated process. To be able to implement appropriate joining methods, with regard to the increasing specification of new body materials, a holistic approach is used at Volvo. This includes a dedicated organization, unique work methodology as well as broad programmes for technology investigation. This paper will describe the idea that lies behind the establishment of the Volvo Joining Centre. It depicts the routines for how the joinability of new material grades for automotive car bodies is evaluated, and presents the global data-base (Join-NET) in which all values for joint properties and joining process data are stored. Furthermore some R&D activities will illustrate the specific conditions that are valid when welding in different grades of extra high strength steels (EHSS). Finally, such an application, which has been successfully introduced in high volume production for recent products, will be more thoroughly described. The work methodology mentioned earlier helped reduce product development time and resulted in a high-quality and smooth introduction without any disturbances in running production.

Tensile and fatigue properties of single lap joints of aluminium alloy/glass fibre reinforced composites fabricated with different joining methods

Adhesive bonding is a constantly developing technique, and the volume of its industrial applications is rapidly increasing, which, in turn, requires improving the compatibility and performance of joining methods in specific applications. The industrial growth of adhesive bonding has also been linked to the broader implementation of composite materials and the increasing number of applications requiring joining dissimilar materials. Compared to traditional joining methods, adhesive bonding does not require local heating of the substrates or introducing holes or notches to them. It is instead a continuous joining method that promotes fewer regions of discontinuities and uniformity of the stress fields. Due to the industrial interest in this method, a substantial effort has been made to expand its range of applications and to provide the design tools that ensure it is a safe, reproducible, reliable, and durable process. The adhesive bonding research field is broad, ranging from adhesive formulation to evaluation of the final bonded structure. The present paper collects the relevant literature and discusses fundamental concepts and recent developments in the adhesive bonding technology, covering three essential topics: adhesive materials, joint designs and joint manufacturing methods, and joint modelling methods. Citing a wealth of relevant review papers, original papers, and book chapters, the paper intends to provide a coherent view of the state of the art, so the reader can identify the opportunities originating from the recent progresses in adhesive bonding.

Metals and plastics have been used in several industrial applications such as automobiles, electronic devices and aircrafts. The joining of their dissimilar materials is important in the fundamental fields of manufacturing. Therefore, we have developed a new Laser-Assisted Metal and Plastic (LAMP) direct joining method with YAG or diode laser, which has many advantages over the conventional bonding methods with adhesives or the mechanical fastening with bolts and nuts. It was found that the LAMP joining method could produce strong joints between various metals and plastics. For example, Type 304 stainless steel and amorphous polyamide (PA) or polyethylene terephthalate (PET) plastic joint samples of 30 mm width possessed tensile shear loads of more than 3,000 N, where the fracture occurred in the base plastic sheets. Tensile shear loads and heat-cycle resistant properties of LAMP joints between SUS 304 and crystalline polyamide (PA) with fibers were also investigated and improved. The LAMP joining was characterized by the formation of small bubbles in the plastic on the metal surface. The mechanism of LAMP joining was interpreted by observing the bonding parts by SEM (Scanning Electron Microscopy) or TEM (Transmission Electron Microscopy), and by analyzing the bonding interface and the gas components inside the bubbles by XPS (X-ray Photoelectron Spectroscopy) and the special method using drilling and Q-mass method, respectively.Metals and plastics have been used in several industrial applications such as automobiles, electronic devices and aircrafts. The joining of their dissimilar materials is important in the fundamental fields of manufacturing. Therefore, we have developed a new Laser-Assisted Metal and Plastic (LAMP) direct joining method with YAG or diode laser, which has many advantages over the conventional bonding methods with adhesives or the mechanical fastening with bolts and nuts. It was found that the LAMP joining method could produce strong joints between various metals and plastics. For example, Type 304 stainless steel and amorphous polyamide (PA) or polyethylene terephthalate (PET) plastic joint samples of 30 mm width possessed tensile shear loads of more than 3,000 N, where the fracture occurred in the base plastic sheets. Tensile shear loads and heat-cycle resistant properties of LAMP joints between SUS 304 and crystalline polyamide (PA) with fibers were also investigated and improved. The LAMP joining was cha...

Research has repeatedly pointed out the suitability of adhesive bonding to substitute to “traditional” joining techniques for numerous materials and loads, including timber to glass. Practitioners, however, are still reluctant to implement them into their designs. Adhesion as a method of joining, particularly in the context of hybrid structures, presupposes knowledge of all involved materials, including codes and procedures; most practitioners however tend to be focused on just a subset of materials. While such specialization is not unusual, it makes it challenging to implement novelty (i.e. new materials or techniques). Additionally, when it comes to adhesion where most of the knowledge has been generated by chemists, the lines become even more blurred. Taking the example of a pedestrian timber-glass bridge, this research shows how design and dimensioning of complex bonded hybrid structures can be performed in accordance with “traditional” engineering practice. The paper guides through every step, from the first concepts to the final design, including the manufacturing, of a relatively complex structure, in which timber and glass act together as equivalent members. The compliance of this process with engineering models is emphasized, and the embedment into existing codes and standards is sought after to ensure acceptancy by practitioners.

The research team proposed to develop innovative multi-scale models to predict corrosion and the resulting mechanical performances in aluminum-steel joints. The methods of joining considered are resistance spot welding, self-piercing riveting, and rivet-welding, all suitable for mass production applications. The multi-scale models integrate high throughput first-principle calculations based on density functional theory (DFT), high throughput calculation of phase diagrams (CALPHAD) modeling, and finite element method (FEM) simulations. These models are to be validated through laboratory experiments. Furthermore, the models are available as open source so as to enable scientists and engineers in the community to adapt and contribute to the development and application. The approaches rely on the research team’s extensive experience on the prediction of properties of individual phases at finite temperatures and variable compositions through DFT calculations, and our broad expertise on dissimilar material joining and their corrosion. The proposed computational framework enables high throughput computations for improved predictions of corrosion and the associated mechanical performance in dissimilar material joints, resulting in significant reduction in computational time needed by the current state-of-the-art methods. With the participation of researchers from three universities, an auto manufacturer, two manufacturing technology/equipment suppliers, and a software developer/vendor, the interdisciplinary research team applies the technical development on both phase-based modeling and laboratory experiments into the automobile body joining processes for validation and technology demonstration. The global cost of corrosion was estimated at about 3.4% of the global GDP in 2013. By using available corrosion control practices, it is estimated a saving between 15- 35% of the cost of corrosion. In the U.S., more than $276 billion is spent repairing corrosion damage. Prediction of the corrosion and its impact on performance of the dissimilar material joints is critical for reducing the massive number of the current corrosion-based recalls for automobiles. Thus, the project goal is to develop models to enable predictive maintenance and end-of-life planning of multi-metal joints with risk of corrosion under different conditions such as exposure to high temperatures in summer and salt solutions in winter, quantified through its pH. An academia-industry consortium led by the University of Michigan and including Pennsylvania State University, University of Illinois Urbana-Champaign, University of Georgia, General Motors Company, Livermore Software Technology Corporation, and Optimal Process Technologies, LLC. created multi-scale models for prediction of corrosion in aluminum-steel joint structures such of them used in vehicle subassemblies – chassis and transmission systems. Starting from the first principle calculations, the team developed mathematical and data-driven models to predict the metallic components, which are formed during joining of two metals, for example aluminum and steel - a lightweight multilateral system which is currently used in more than 60% car bodies. These models were used for simulating chemical reactions that are happening when the joining metallic components are exposed to high temperatures and different pH values. The team was able to predict how the corrosion installs on the metallic components and how they lead to a sudden failure of components in cars. Newly developed machine learning algorithms combining Science, Technology, Engineering and Math disciplines, advanced finite element simulation and experimental validations have been integrated in a platform for prediction of the corrosion evolution and prediction the failure of joints under mechanical loadings and fatigue. Moreover, based on machine learning and inverse analysis, the team proposed solutions for designing new metallic alloys less susceptible to corrosion when joining multi-material assembles. An average of 4% error compared with experiments was achieved for the most common joints that are used in vehicle subassemblies.

Material issues pose a significant challenge for the design of future fusion reactors. These issues require new advanced materials to be developed. W‐fiber‐reinforced W‐composite material (W f/W) incorporates extrinsic toughening mechanisms increasing the resistance against failure and thus granting steps toward application in a future fusion reactor. W f/W can be produced based on chemical vapor deposition or powder metallurgical routes. In this contribution, the efforts of upscaling the production of W f/W will be reviewed based on recent results. In addition, the activities related to enabling large‐scale production for new fusion applications are being studied. Herein, two main achievements are to be highlighted. First, an upscaled production is established to produce flat tile samples for joining tests on copper and steel, and second, a new method of joining W f/W on copper is established and tested under high heat‐flux conditions.

<div class="htmlview paragraph">This paper details five types of adhesives used in the automotive industry: evaporation or diffusion, chemically reactive, pressure sensitive, hot melts, and sealants. The adhesives included in each group are listed, along with their properties. The author feels that adhesives offer the best method of joining because of their ability to supply a uniform distribution of stresses, an air and water tight seal, vibration and sound dampening, protection from galvanic corrosion, fatigue resistance, along with the ability to join widely dissimilar materials.</div> <div class="htmlview paragraph">Eight tables summarize the various types of adhesive and their uses, bases, applications, and special properties.</div>

Methods of joining

The aim of this article is a presentation of the results of laboratory tests and numerical and analytical modeling of timber-concrete composite beams with semi-rigid joints made of steel plates and convex nails. Due to good quality of used materials, composite timber-concrete constructions are considered a suitable solution for new buildings and reconstructions of ceiling constructions of residential and civil buildings. There are numerous ways to create a connection (joint) between timber beam and concrete slab. The methods of coupling are more and more sophisticated which carries considerable demands on control of implementation and technological practice.

Presented the assumptions of the Reportable Food Registry (RFR), which was established in the United States by the Food and Drug Administration (FDA). Examined in which way the most frequently reported hazards were related to commodities, using the cluster analysis (method of joining). Presented these relationships in tree diagrams. Indicated the disadvantages of the RFR, but also some possibilities of comparison of the RFR entries and the European Rapid Alert System for Food and Feed (RASFF) notifications.

The author highlights the problems of alabaster monuments and emphasizes the need to respect the original polychromy. The processes of deterioration of alabaster monuments are described. Suitable cleaning methods, including recipes for the removal of dirt and grease are given. The problems of consolidation of alabaster are discussed and suitable consolidants and adhesives named. Methods of joining, using dowels and cramps and rebuilding monuments to prevent problems from rising damp are also described.