METHOD OF PRODUCING STRUCTURAL CERAMICS BY ADDITIVE TECHNOLOGY FOR ARTICLES OF COMPLEX GEOMETRY Russian patent published in 2024 - IPC C04B35/573 C04B35/65 B33Y40/20 B22F3/105 

FIELD: various technological processes.

SUBSTANCE: invention relates to production of structural ceramic materials based on silicon carbide for making articles of complex geometrical shape, having high heat resistance and wear resistance, for use in machine building, marine and aircraft engineering. Silicon carbide powder is clad with calculated amount of carbon. For cladding, a mixture of powdered carbide materials is used at a ratio of coarse fraction/fine fraction of 6/4 by weight. Produced powder is compacted by selective laser fusion into preset three-dimensional shape. Formation of composite layers of material with silicon carbide matrix at additive plant is characterized by the following process modes: protective medium (argon or vacuum), the speed of the laser (or scanning the specified surface area with a laser beam) in range of 50–100 mm/s, the laser radiation power in range of 40–100 W, diameter of the laser spot on the surface area is in range of 80–100 mcm, the thickness of a single fused layer (roll pitch) is not more than 50 mcm. Track pitch or laser displacement during track formation is 10–30 mcm. Obtained primary workpiece is placed on a substrate of hexagonal boron nitride and sprinkled with high-purity silicon in a calculated amount, after which sintering is carried out in a vacuum at temperature of 1,500–1,600 °C for 20–30 minutes.

EFFECT: formed ceramic articles of complex geometrical shape with relative density 0,95–0,99, hardness 20–40 GPa, phase homogeneity and stability up to 1,300 °C during operation in vacuum, shrinkage of not more than 1 vol.%.

3 cl, 2 ex