Welding and joining by combustion synthesis

As a highly exothermic process, combustion synthesis can be used for welding and joining. Welding and joining by combustion synthesis is generally characterized with simple equipment, a short processing time, and low energy consumption. Moreover, it is capable of joining very refractory materials and dissimilar materials with a functionally graded joint layer to reduce thermal stress. This chapter focuses on welding and joining by combustion synthesis. First, the thermite welding of rails is introduced, including processing, facilities, heat transfer, temperature distribution, and the mechanical properties, fatigue performance, and failure mechanism of welds. Then, other methods of joining by combustion synthesis are discussed, such as reactive joining, reactive resistance joining, joining by microwave or laser-assisted combustion synthesis, and joining by reactive foils. Finally, repair by combustion synthesis is also mentioned.