Effect of active filler on joining property of silicon carbide to itself by polysilazane

Joining of pressureless sintering silicon carbide to itself has been realized using vinyl-containing polysilazane with aluminium nanopowders as joining materials.The joining strength of the joints is strongly affected by adding aluminium nanopowders.Addition of aluminium nanopowders as an active addition can effectively accelerate pyrolysis of polysilazane, lower joining temperature and reduce holes and cracks in the joining interlayer.Therefore it can enhance the joining strength.The maximum bending strength of the joints is 146.8 MPa.This value is obtained at the joining temperature of 1150℃ and after the reinforcement for 2 times.XRD study reveals that the joining material has transformed into an amorphous SiCN ceramic and SiC, Si₃N₄, AlN crystallites.The thickness of interlayer is abaut 5 μm.The joining interlayer is uniform, and the contact at the interfaces is good.