Abstract:
An electrothermal shock-assisted high-temperature brazing technology was proposed in this work, which successfully achieved the joining of 18.77Gd
2O
3-4.83Y
2O
3-28.22TiO
2-8.75ZrO
2-39.43Al
2O
3 multicomponent oxide filler and SiC ceramics. The SiC brazed joint with an optimal shear strength of 136.27 MPa was achieved under 20 A DC current and 800 W cut-off power by using carbon fiber as the heating element. The Al
2O
3 and TiO
2 components in the multi-component oxide filler metal were very important to achieve a good SiC ceramic brazing joint. TiO
2 reacted with SiC at high temperature to generate a Ti-rich interfacial reaction layer with a thickness of ~10 μm at the interface, and Al
2O
3 penetrated into the base metal to form a pinning effect, which was beneficial to improve the brazed joint strength. However, when the heat input was too large, the SiC base metal would decompose seriously, and a large amount of C element would diffuse to the brazing seam, resulting in obvious crack defects. The shear strength would be reduced to ~60 MPa, and the fracture completely occurred in the brazing seam.