Real-Time Weld Process Monitoring

Welding is a complex process, is increasingly automated, and operates at higher speeds in more difficult environments. Defects also need to be detected as they arise to ensure efficient, high-quality production. All these needs have led to a growing interest in the use of sensors to provide accurate, robust, real-time monitoring where this cannot be achieved by more traditional testing and inspection techniques. This important book reviews the range of monitoring techniques available and their applications. After an introductory chapter, the first part of the book reviews the range of sensor technologies in welding, from arc and optical sensors to infrared and ultrasonic techniques. Part two discusses the monitoring of particular aspects of welding such as weld seams and profiles, the analysis of weld penetration and weld pool surface, as well as monitoring of resistance and laser welding. With its distinguished editor and international team of contributors, Real-time weld process monitoring is a valuable reference to all those concerned with improving the quality of welding and welded components. Reviews the range of monitoring techniques available Examines the range of sensor technologies in welding from arc and optical sensors to infrared and ultrasonic techniques Discusses the monitoring of specific aspects of welding such as weld seams, resistance and laser welding

Many new, or relatively new, welding processes such as friction stir welding, resistance spot welding and laser welding are being increasingly adopted to replace or improve on traditional welding techniques. Before advanced welding techniques are employed, their potential failure mechanisms should be well understood and their suitability for welding particular metals and alloys in different situations should be assessed. Failure mechanisms of advanced welding processes provides a critical analysis of advanced welding techniques and their potential failure mechanisms. The book contains chapters on the following topics: Mechanics modelling of spot welds under general loading conditions and applications to fatigue life predictions, Resistance spot weld failure mode and weld performance for aluminium alloys, dual phase steels and TRIP steels, Fatigue behaviour of spot welded joints in steel sheets, Non-destructive evaluation of spot weld quality, Solid state joining - fundamentals of friction stir welding, Failure mechanisms in friction stir welds, Microstructure characteristics and mechanical properties of laser weld bonding of magnesium alloy to aluminium alloy, Fatigue in laser welds, Weld metal ductility and its influence on formability of tailor welded blanks, Joining of lightweight materials using reactive nanofoils, and Fatigue life prediction and improvements for MIG welded advanced high strength steel weldments. With its distinguished editor and international team of contributors, Failure mechanisms of advanced welding processes is a standard reference text for anyone working in welding and the automotive, shipbuilding, oil and gas and other metal fabrication industries who use modern and advanced welding processes. Provides a critical analysis of advanced welding techniques and their potential failure mechanisms Experts in the field survey a range of welding processes and examine reactions under various types of loading conditions Examines the current state of fatigue life prediction of welded materials and structures in the context of spot welded joints and non-destructive evaluation of quality

The Army Materials and Mechanics Research Center in cooperation with the Office of Sponsored Programs of Syracuse University has been conducting the Annual Sagamore Army Materials Research Conferences since 1954. The specific purpose of these conferences has been to bring together scientists and engineers from academic institutions, industry and government to explore in depth a subject of importance to the Department of Defense, the Army, and the scientific community. This 30th Sagamore Conference, entitled Innovations in Materials Processing, has attempted to focus on the inter disciplinary nature of materials processing, looking at recent advancements in the development of unit processes from a range of standpoints from the understanding and control of the under lying mechanisms through their application as part of a manufactur ing sequence. In between, the classic link between processing and materials properties is firmly established. A broad range of materials are treated in this manner: metals, ceramics, plastics, and composites. The interdisciplinary nature of materials processing exists through its involvement with the basic sciences, with, process and product design, with process control, and ultimately with manufacturing engineering. Materials processing is interdisciplinary in another sense, through its application within all materials disciplines. The industrial community (and the Army as its customer) is becoming increasingly concerned with producibility/reliability/ affordability issues in advanced product development. These concerns will be adequately addressed only by employing the full range of disciplines encompassed within the field of materials processing.

Designed for courses in basic welding and welding technology, this introductory welding text contains coverage of the codes, materials, and processes necessary to become proficient in a complex industry. The technology of welding is growing and the book's focus on arc welding processes and the use of steel in construction reflect those changes while also providing coverage of basic principles and theory.

An improved method and apparatus are provided for real time weld monitoring. An infrared signature emitted by a hot weld surface during welding is detected and this signature is compared with an infrared signature emitted by the weld surface during steady state conditions. The result is correlated with weld penetration. The signal processing is simpler than for either UV or acoustic techniques. Changes in the weld process, such as changes in the transmitted laser beam power, quality or positioning of the laser beam, change the resulting weld surface features and temperature of the weld surface, thereby resulting in a change in the direction and amount of infrared emissions. This change in emissions is monitored by an IR sensitive detecting apparatus that is sensitive to the appropriate wavelength region for the hot weld surface.