This book presents recent material science-based and mechanical analysis-based advances in joining processes. It includes all related processes, e.g. friction stir welding, joining by plastic deformation, laser welding, clinch joining, and adhesive bonding, as well as hybrid joints. It gathers selected full-length papers from the 1st Conference on Advanced Joining Processes.

This report supplies information on joining processes applicable to titanium and its alloys in sheet metal applications, primarily related directly to airframe construction. Although the material presented here does not cover all titanium joining processes, and omits such processes as plasma-arc, submerged-arc, electroslag, flash, and high-frequency resistance welding, the data presented cover materials up to 2-inches thick in some cases and the report should be useful to anyone seeking titanium joining information. The joining processes covered fall into five categories: welding, brazing, metallurgical bonding (diffusion and deformation bonding), adhesive bonding, and mechanical fastening. The fusion welding processes that are discussed in detail include gas tungsten arc, gas metal arc, arc spot, and electron beam. The resistance processes give extended coverage are spot, roll spot, and seam welding. (Author).

Solid state joining of titanium via friction stir welding and diffusion bonding have emerged as enablers of efficient monolithic structural designs by the eliminations fasteners for the aerospace industry. As design complexity and service demands increase, the need for joints of dissimilar alloys has emerged. Complex thermomechanical conditions in friction stir weld joints and high temperature deformation behavior differences between alloys used in dissimilar joints gives rise to a highly variable flow pattern within a stir zone. Experiments performed welding Ti-6Al-4V to ß21S show that mechanical intermixing of the two alloys is the primary mechanism for the generation of the localized chemistry and microstructure, the magnitude of which can be directly related to pin rotation and travel speed weld parameters. Mechanical mixing of the two alloys is heavily influenced by strain rate softening phenomena, and can be used to manipulate weld nugget structure by switching which alloy is subjected to the advancing side of the pin. Turbulent mixing of a weld nugget and a significant reduction in defects and weld forces are observed when the ß21S is put on the advancing side of the weld where higher strain rates are present. Chemical diffusion driven by the heat of weld parameters is characterized using energy dispersive x-ray spectroscopy (EDS) and is shown to be a secondary process responsible for generating short-range chemical gradients that lead to a gradient of alpha particle structures. Diffusion calculations are inconsistent with an assumption of steady-state diffusion and show that material interfaces in the weld nugget evolve through the break-down of turbulent interface features generated by material flows. A high degree of recrystallization is seen throughout the welds, with unique, hybrid chemistry grains that are generated at material interfaces in the weld nugget that help to unify the crystal structure of dissimilar alloys. The degree of recrystallization is tied to the localized thermal profile in the weld nugget as well as the heating rates of a given set of weld parameters. Slow kinetics of alpha dissolution relative to the heating rate and process times of friction stir welding suggest an alpha-particle assisted super-transus recrystallization process contributes to a refined grain size in weld parameters utilizing high travel speed.

Joining Processes for Dissimilar and Advanced Materials describes how to overcome the many challenges involved in the joining of similar and dissimilar materials resulting from factors including different thermal coefficients and melting points. Traditional joining processes are ineffective with many newly developed materials. The ever-increasing industrial demands for production efficiency and high-performance materials are also pushing this technology forward. The resulting emergence of advanced micro- and nanoscale material joining technologies, have provided many solutions to these challenges. Drawing on the latest research, this book describes primary and secondary processes for the joining of advanced materials such as metals and alloys, intermetallics, ceramics, glasses, polymers, superalloys, electronic materials and composites in similar and dissimilar combinations. It also covers details of joint design, quality assurance, economics and service life of the product. Provides valuable information on innovative joining technologies including induction heating of metals, ultrasonic heating, and laser heating at micro- and nanoscale levels Describes the newly developed modelling, simulation and digitalization of the joining process Includes a methodology for characterization of joints

Joining Processes is aimed at scientists and engineers who need to specify effective means of joining metals and ceramics, and also for undergraduates whose studies encompass joining processes. Joining Processes provides a brief review of the spectrum of joining processes ranging from fusion welding to adhesive bonding, followed by a detailed introduction to brazing, diffusion bonding and their hybrid processes. This book also describes the scientific principles of the joining processes and provides practical information about the optimum selection of joining materials, joint designs and processing parameters. The effects of both similarities and significant differences of the processes on joint properties are emphasised and illustrated by descriptions of case histories of successful applications.