Reactive air brazing of Ti3AlC2 ceramic with Ag–CuO fillers: Microstructure and joint properties

In this work, Ti 3 AlC 2 ceramics were joined by reactive air brazing using Ag–CuO fillers. The Ag–4CuO filler showed the best wettability, with a minimum contact angle of 13.1°. Continuous and dense brazed seams were formed at 1000 °C-1100 °C. The joint interface consisted of an Ag–rich brazed seam and a TiO 2 /α-Al 2 O 3 layered reaction zone. Increasing brazing temperature, the reaction layer evolved from TiO 2 –dominated products with limited Al 2 O 3 to a TiO 2 /Al 2 O 3 /TiO 2 trilayer structure, whereas increasing CuO content thickened the oxide reaction layer. The maximum shear strength reached 72.2 MPa at 1050 °C for 30 min with 4 mol.% CuO. Fracture was dominated by brittle features, with fracture regions varying with the reaction-layer structure. These results provide experimental guidance for reactive air brazing of Ti 3 AlC 2 ceramics.