METHOD FOR PRODUCING HIGH-ENTROPY ALLOY BORIDE Russian patent published in 2023 - IPC C22C1/51 B22F3/12 C04B35/58 

FIELD: powder metallurgy.

SUBSTANCE: production of high-entropy boride ceramics resistant to high-temperature oxidizing gas flow. It can be used for the manufacture of parts operated at elevated temperatures, loads and in aggressive environments. Powders of at least five metals selected from the series Ti, V, Zr, Nb, Hf, Ta, W, Mo with a purity of at least 99.5% are mixed in an equiatomic ratio in a sealed box filled with argon. Mechanical alloying is carried out in an attritor using stainless steel balls with a diameter of 5-15 mm as grinding bodies at a ratio of the mass of balls to the mass of powder 10:1-40:1 at a stirrer rotation speed of 150 to 350 rpm for 5-25 hours. Polycrystalline boron powder and doped powder are mixed in a ratio of 2:1 in an attritor for 15-30 minutes until a homogeneous mechanical mixture is obtained, the resulting mechanical mixture is poured into a graphite mold and placed in a vacuum. Spark plasma sintering is carried out at a temperature of 1600-2200°C, load 15-70 MPa, heating rate 100°C/min and exposure 1-5 minutes to obtain a compact material.

EFFECT: obtaining ceramics with high relative density, resistance in high-temperature gas oxidizing flow, compressive strength and hardness.

1 cl, 3 ex