Localized Heating Joining for Ceramic Matrix Composites

Current and well-known joining methods such as welding, adhesive or mechanical joining are not the best choice for ceramic matrix composites (CMC): CMC do not melt and they are supposed to be used for high-temperature applications (i.e., higher than 1000–1200 °C), thus ruling out the use of polymeric adhesives, most of brazing and glass-based options, and of metal-based mechanical joining such as bolts, rivets, etc. Joining CMC poses several unique challenges, mainly because a simple and user-friendly localized, pressure-less, and possibly deployable on-field joining method is nowadays unavailable. Current joining technologies for CMC often struggle to achieve reliable bonds without compromising the final component’s integrity and its high-temperature performance. Additionally, in most cases, the entire CMC component is heated to obtain the joint. Localized heating techniques offer a promising solution by avoiding heating the entire component, thus minimizing thermal stress, achieving precise control over the bonding process, and finally saving energy. This chapter reviews the advancements in localized heating joining methods for CMC, focusing on techniques such as induction/electric heating, microwave heating, and laser-assisted joining. Each method’s principles, advantages, and limitations are discussed, along with case studies highlighting successful applications in nuclear, aerospace, automotive, and other industrial sectors. The paramount importance lies in the comprehensive understanding of how specific process parameters directly influence the resultant quality of the joint. This critical analysis is fundamentally integrated with the strategic incorporation of these advanced methods into existing manufacturing workflows. The ultimate objective of this integration is to achieve a significant enhancement in the overall structural performance and to ensure the long-term reliability of ceramic matrix composite components.