Flash joining of conductive ceramics in a few seconds by flash spark plasma sintering

The feasibility of flash joining conductive ceramics using spark plasma sintering is demonstrated. It is shown that graphite disks can be joined in a few seconds (6-10 s electric discharge time) using a SiOC precursor (methyl silicone resin) as an interlayer. Differently from usual flash experiments, the process does not require any preheating, allowing a dramatic reduction of the processing time. XPS analysis of the joint revealed a clear evolution of the chemical environment of silicon with a progressive transition from SiOC to SiO2/SiC. Mechanical tests were performed to determine the fracture toughness (1.0 +/- 0.2 MPa m(0.)(5)) and fracture energy (40.6 +/- 9.8 J/m(2)) of the interface Flash joining can be applied beyond graphite joining, and opens a novel and flexible processing route for many conductive ceramics, as demonstrate by preliminary work on Kanthal (R) Super MoSi2 and C-f-reinforced SiC.