Hydrothermal-corrosion-resistant and high-temperature-oxidation-resistant silicon carbide ceramic weldment as well as preparation method and application thereof

The invention belongs to the technical field of ceramic welding, and discloses a hydrothermal corrosion and high-temperature oxidation resistant silicon carbide ceramic weldment and a preparation method and application thereof.The method comprises the steps that Al2O3, MgO, CaO, HfO2, Nd2O3 and SiO2 powder are subjected to ball milling and mixing, water quenching is conducted at the temperature of 1600-1700 DEG C to obtain glass, glass powder is obtained through grinding, refining and sieving, the glass powder is subjected to dry pressing forming to obtain a glass green body, the glass green body is subjected to sintering, and the silicon carbide ceramic weldment is obtained. The glass block is placed in the to-be-welded areas of the two SiC ceramics, then the two SiC ceramics are placed according to the structure of a to-be-formed product to obtain a to-be-connected assembly, the to-be-connected assembly is placed in a heating furnace to be subjected to heat treatment at the temperature of 1350-1600 DEG C in