Roll bonding (RB) describes solid-state manufacturing processes where cold or hot rolling of plates or sheet metal is carried out for joining similar and dissimilar materials through the principle of severe plastic deformation. This review covers the mechanics of RB processes, identifies the key process parameters, and provides a detailed discussion on their scientific and/or engineering aspects, which influence the microstructure–mechanical behavior relations of processed materials. It further evaluates the available research focused on improving the metallurgical and mechanical behavior of bonded materials such as microstructure modification, strength enhancement, local mechanical properties, and corrosion and electrical resistance evolution. Moreover, current applications and advantages, limitations of the process and developments in dissimilar material hot roll bonding technologies for producing titanium to steel and stainless steel to carbon steel ultra-thick plates are also discussed. The paper concludes by deliberating on the bonding mechanisms, engineering guidelines and process–property–structure relationships, and recommending probable areas for future research.

This study presents detailed analyses of variant joining processes under the category of friction stir riveting (FSR) that are applied to assemble similar or dissimilar materials by integrating the advantages of both friction stir process and mechanical fastening. It covers the operating principle of FSR methods along with the insights into various process parameters responsible for successful joint formation. The paper further evaluates the researches in friction stir-based riveting processes, which unearth the enhanced metallurgical and mechanical properties, for instance microstructure refinement, local mechanical properties and improved strength, corrosion, and fatigue resistance. Advantages and limitations of the FSR processes are then presented. The study is concluded by summarizing the key analyses and proposing the potential areas for future research.

This study presents a brief account of the seminal works on aeroelastic tailoring for aerospace applications. Tailoring using advanced composites is a revolutionary process in the ever-evolving realm of aerospace design. The rapid growth in scientific knowledge and research necessitates the consolidation of the latest research and technological advancements every few years. The current work is part of this process. The major portion of the study covers the latest developments and state-of-the-art research in this century, with a special focus on the last ten years. However, a brief account of the historical background, the theoretical foundation, and a few seminal works from the later part of the previous century and the early part of this century have also been included to form a comprehensive starting point for new researchers entering the field of aeroelastic tailoring and to assist them in identifying the directions of their future endeavours. A critical evaluation of different research contributions, including their advantages, limitations, and prospects for future work, has been presented. Emphasis has been laid on flutter mitigation and aeroelastic optimization for passive aeroelastic control. New material and structural technologies (like curvilinear fibres, tow steering, functional grading, thickness distributions, selective reinforcing, additive manufacturing, and unconventional structural configurations), and novel tailoring optimization techniques (like lamination parameters, blending constraints, active aeroelastic wing design, shape functions, surrogate modelling, reduced order modelling, uncertainty quantification, matrix perturbation theory, modal-strain-energy analyses, and multiple indigenous optimization algorithms) have been identified as active research areas and prospective enabling tools for future work. The challenges faced in the full-scale employment of aeroelastic tailoring include quick, robust, and cost-effective optimization to cater for all design variables and constraints, experimental validation of new methodologies, certification of new material and structural configurations through relevant bodies and standards and gaining the confidence of industrialists for investment in technologies with a few highly focused areas of applications.