MIXED OXIDE-NITRIDE-CARBIDE CUTTING CERAMICS AND METHOD OF ITS PRODUCTION Russian patent published in 2024 - IPC C22C1/10 B22F3/14 C22C29/00 C04B35/01 B23B27/14 

FIELD: powder metallurgy.

SUBSTANCE: invention relates to powder metallurgy, particularly, to production of cutting plate from mixed oxide-nitride-carbide cutting ceramic. It can be used to equip cutting tools for processing hard-to-machine steels of “12X18H9T” and “14X17H2” grades and hard-to-machine alloys and materials, as well as high-strength white and grey cast irons on metal-working machines. Mixed oxide-nitride-carbide cutting ceramic contains, wt.%: silicon oxide SiO₂ 30, silicon nitride Si₃N₄ 30, cobalt carbide Co₂C 10, titanium carbide TiC 10, zirconium carbide ZrC 10, tungsten carbide WC 10. Mixture of silicon oxide and silicon nitride is calcined at temperature of 1,900-1,950 °C and subjected to fine vibration grinding for 3.8-5.2 hours. Then the basic composition is mixed with cobalt carbide, titanium carbide, tungsten carbide and zirconium carbide till uniform distribution in volume, deoxidizing additives of catalysts are added and subjected to spray drying. Obtained mixture is pressed to form a cutting plate, then sintered at temperature of 4,000-4,050 °C and subjected to short-term annealing with holding for 10.0-15.0 min at temperature of 1,900-1,950 °C. Sintered plates are machined to produce the roughness of the faces Ra=0.04-0.06 mcm.

EFFECT: higher intergranular corrosion resistance, temperature wear resistance, hardness, stability, ductility, impact strength and operability, increased strength and hardness.

2 cl, 1 tbl